Posts

Probiotics vs. prebiotics: Which to choose? And when?

/in Consumer Blog, ISAPP Science Blog /by KC

By Dr. Karen Scott, PhD, Rowett Institute, University of Aberdeen, Scotland

As consumers we are constantly bombarded with information on what we should eat to improve our health. Yet the information changes so fast that it sometimes seems that what was good for us last week should now be avoided at all costs!

Probiotics and prebiotics are not exempt from such confusing recommendations, and one area lacking clarity for many is which of them we should pick, and when. In this blog I will consider the relative merits of probiotics and prebiotics for the gut environment and health.

By definition, both probiotics and prebiotics should ‘confer a health benefit on the host’. Since an improvement in health can be either subjective (simply feeling better) or measurable (e.g. a lowering in blood pressure) it is clear that there is not a single way to define a ‘health benefit’. This was discussed nicely in a previous blog by Prof Colin Hill.

Although consumption of both probiotics and prebiotics should provide a health benefit, this does not mean that both need to act through the gut microbiota. Prebiotics definitively need to be selectively utilised by host microorganisms – they are food for our existing microbiota. However, depending on the site of action, this need not be the gut microbiota, and prebiotics targeting other microbial ecosystems in or on the body are being developed. Traditionally prebiotics have specifically been used to boost numbers of gut bacteria such as Bifidobacterium and the Lactobacilliaceae family, but new prebiotics targeting different members of the gut microbiota are also currently being researched.

Probiotics are live bacteria and despite a wealth of scientific evidence that specific probiotic bacterial strains confer specific health benefits, we often still do not know the exact mechanisms of action. This can make it difficult both to explain how or why they work, and to select new strains conferring similar health benefits. Many probiotics exert their effects within the gut environment, but they may or may not do this by interacting with the resident gut microbiota. For instance probiotics that reduce inflammation do so by interacting directly with cells in the mucosal immune system. Yet strains of lactobacilli (see here for what’s included in this group of bacteria) may do this by modulating cytokine production while Bifidobacterium strains induce tolerance acquisition. These very different mechanisms are one reason why mixtures containing several probiotic species or strains may in the end prove the most effective way to improve health. On the other hand, some probiotics do interact with the resident gut microbes: probiotics that act by inhibiting the growth of pathogenic bacteria clearly interact with other bacteria. Sometimes these may be potential disease-causing members of the resident microbiota, normally kept in check by other commensal microbes that themselves have become depleted due to some external impact, and some may be incoming pathogens. Such interactions can occur in the gut or elsewhere in the body.

This brings me back to the original question, and one I am frequently asked – should I take a probiotic or a prebiotic? The true and quick answer to this question is ‘it depends’! It depends why you are asking the question, and what you want to achieve. Let’s think about a few possible reasons for asking the question.

I want to improve the diversity of my microbiota. Should I take a prebiotic or a probiotic?

My first reaction was that there is an easy answer to this question – a prebiotic. Prebiotics are ‘food’ for your resident bacteria, so it follows that if you want to improve the diversity of your existing microbiota you should take a prebiotic. However, in reality this is too simplistic. Since prebiotics are selectively utilised by a few specific bacteria within the commensal microbiota to provide a health benefit, taking a prebiotic will boost the numbers of those specific bacteria. If the overall bacterial diversity is low, this may indeed improve the diversity. However, if the person asking the question already has a diverse microbiota, although taking one specific prebiotic may boost numbers of a specific bacterium, it may not change the overall diversity in a measurable way. In fact the best way to increase the overall diversity of your microbiota is to consume a diverse fibre-rich diet – in that way you are providing all sorts of different foods for the many different species of bacteria living in the gut, and this will increase the diversity of your microbiota.  Of course, if you already consume a diverse fibre-rich diet your microbiota may already be very diverse, and any increased diversity may not be measurable.

I want to increase numbers of bifidobacteria in my microbiota. Should I take a prebiotic or a probiotic?

Again, I initially thought this was easy to answer – a prebiotic. There is a considerable amount of evidence that prebiotics based on fructo-oligosaccharides (FOS or inulin) boost numbers of bifidobacteria in the human gut. But this is only true as long as there are bifidobacteria present that can be targeted by consuming suitable prebiotics. Some scientific studies have shown that there are people who respond to prebiotic consumption and people who do not (categorised as responders and non-responders). This can be for two very different reasons. If an individual is devoid of all Bifidobacterium species completely, no amount of prebiotic will increase bifidobacteria numbers, so they would be a non-responder. In contrast if someone already has a large, diverse bifidobacteria population, a prebiotic may not make a meaningful impact on numbers – so they may also be a non-responder.

However, for those people who do not have any resident Bifidobacterium species, the only possible way to increase them would indeed be to consume a probiotic- specifically a probiotic containing one or several specific Bifidobacterium species. Consuming a suitable diet, or a prebiotic alongside the probiotic, may help retention of the consumed bifidobacteria, but this also depends on interactions with the host and resident microbiota.

I want to increase numbers of ‘specific bacterium x’ in my microbiota. Should I take a prebiotic or a probiotic?

The answer here overlaps with answer 2, and depends on the specific bacterium, and what products are available commercially, but the answer could be to take either, or a combination of both – i.e. a synbiotic.

If bacterium x is available as a probiotic, consuming that particular product could help. If bacterium x has been widely researched, and the specific compounds it uses for growth have been established, identifying and consuming products containing those compounds could boost numbers of bacterium x within the resident microbiota. Such research may already have identified combination products – synbiotics – that could also be available.

One caveat for the answers to questions 2 and 3 is that probiotics do not need to establish or alter the gut microbiota to have a beneficial effect on health. In fact, a healthy large intestine has a microbial population of around 1011-1012 bacterial cells per ml, or up to 1014 cells in total, while a standard pot of yogurt contains 1010 bacterial cells (108 cells/ml). Assuming every probiotic bacterial cell reaches the large intestine alive, they would be present in a ratio of 1: 10,000. This makes it difficult for them to find a specific niche to colonise, so consuming a probiotic may not “increase numbers of ‘specific bacterium x’ in my microbiota”, but this does not mean that the function of the probiotic within the gut ecosystem would not provide a health benefit. Many probiotics act without establishing in the microbiota.

I’ve been prescribed antibiotics. Should I take a prebiotic or a probiotic?

In this case the answer is clear cut – a probiotic.

There is a lot of evidence that consumption of probiotics can alleviate symptoms of, or reduce the duration of, antibiotic associated diarrhoea. From what we know about mechanisms of action, consumption of antibiotics kills many resident gut bacteria, reducing the overall bacterial population and providing an opportunity for harmful bacteria to become more dominant. Consuming certain probiotics can either help boost bacterial numbers in the large intestine, preventing the increased growth in pathogenic bacteria until the resident population recovers, or can increase production of short chain fatty acids, decreasing the colonic pH, preventing growth of harmful bacteria. Ideally probiotics would be taken alongside antibiotics, from day 1, to avoid the increase in numbers of the potentially harmful bacteria in the first place. This has been shown to be more effective. Consuming the probiotic alongside prebiotics that could help the resident microbiota recover more quickly may be even more effective. Even if you’ve already started the course of antibiotics, it’s not too late to start taking probiotics to reduce any side-effects. Always remember to complete taking the course of antibiotics as prescribed.

 

 

Putting all of this together to answer the initial question of whether it’s better to take probiotics or prebiotics, a better answer may in fact be take both to cover the different effects each has, maximising the benefit to health. There are specific times when probiotics are better, and other times when prebiotics are better, and consuming both together may make each more effective. In any case care has to be taken to consume a product that has been confirmed through robust studies to have the specific benefit that is required.

 

Episode 3: The science of fermented foods, part 2

/in Podcast, Season One /by KC

Podcast: Play in new window | Download

Subscribe: Apple Podcasts | Spotify | RSS

The Science, Microbes & Health Podcast 

This podcast covers emerging topics and challenges in the science of probiotics, prebiotics, synbiotics, postbiotics and fermented foods. This is the podcast of The International Scientific Association for Probiotics and Prebiotic (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

The science of fermented foods, part 2, with Prof. Bob Hutkins

Episode summary:

Before listening to this episode, it’s recommended that you check out episode #1, The science of fermented foods, Part 1. In this episode, the hosts continue their discussion of fermented foods with Prof. Bob Hutkins, University of Nebraska – Lincoln. Prof. Hutkins elaborates on how the microbes associated with fermented foods may confer health benefits, as well as how food scientists choose strains for fermentation. He emphasizes how the live microbes in fermented foods differ from probiotics.

Key topics from this episode:

  • Why working in the field of fermented foods is exciting and rewarding
  • The challenges for scientists, especially when it comes to designing clinical studies with various fermented foods
  • The benefits of fermented foods – from being safe as well as nutritious, to the health benefits that live microbes present in the foods can provide
  • How microbes are selected for fermentation; companies focus on strain performance – i.e., good growth and survival to preserve the food and provide a desired flavor and texture
  • The activities of live microbes present in fermented foods, from initiating the fermentation process to benefiting human health
  • The differences between probiotics and live microbes in fermented foods
  • How live microbes in fermented foods might affect your gut microbiota and why some scientists believe that fermented foods are important for getting regular doses of live microbes

 

Episode links:

Microbiology and Technology of Fermented Foods, 2nd Ed., by Robert W. Hutkins
The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods
The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic
Gut-microbiota-targeted diets modulate human immune status, study by Stanford researchers

 

Additional resources:

Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of postbiotics.
Postbiotics. ISAPP infographic
Fermented foods. ISAPP infographic
What are fermented foods? ISAPP video
Do fermented foods contain probiotics? ISAPP blog post
How are probiotic foods and fermented foods different? ISAPP infographic
Are fermented foods probiotics? Webinar by Mary Ellen Sanders, PhD

 

About Prof. Bob Hutkins:

Bob Hutkins is the Khem Shahani Professor of Food Microbiology at the University of Nebraska. He received his Ph.D. from the University of Minnesota and was a postdoctoral fellow at Boston University School of Medicine. Prior to joining the University of Nebraska, he was a research scientist at Sanofi Bio Ingredients.

The Hutkins Lab studies bacteria important in human health and in fermented foods. His group is particularly interested in understanding factors affecting persistence and colonization of probiotic bacteria in the gastrointestinal tract and how prebiotics shift the intestinal microbiota and metabolic activities. The lab also conducts clinical studies using combinations of pro- and prebiotics (synbiotics) to enhance health outcomes. More recently we have developed metagenome-based models that can be used in personalized nutrition.

Professor Hutkins has published widely on probiotics, prebiotics, and fermented foods and is the author of the recently published 2nd edition of Microbiology and Technology of Fermented Foods.

Episode 2: Why mechanistic research on probiotics is captivating and important

/in Podcast, Season One /by KC

Podcast: Play in new window | Download

Subscribe: Apple Podcasts | Spotify | RSS

The Science, Microbes & Health Podcast 

This podcast covers emerging topics and challenges in the science of probiotics, prebiotics, synbiotics, postbiotics and fermented foods. This is the podcast of The International Scientific Association for Probiotics and Prebiotic (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

Why mechanistic research on probiotics is captivating and important, with Prof. Maria Marco

Episode summary:

In this episode, the ISAPP hosts discuss probiotic mechanisms of action with Prof. Maria Marco, University of California, Davis. Prof. Marco is a well-known probiotic researcher with special expertise in food-associated lactobacilli. Here she explains how studying probiotics in food science can lead to fundamental insights in biology. She shares why it’s important to understand probiotic mechanisms of action, and describes how scientists go about identifying which compounds or pathways are important for probiotic health effects.

Key topics from this episode:

  • The search for probiotic mechanisms of action: why this research is essential and the added value of this type of research for the end consumer.
  • What we now understand about probiotic mode of action: probiotic mode of action for different strains is mediated by multiple working mechanisms, from cell-wall-associated molecules to bacteriocin production and metabolite synthesis.
  • How researchers set the stage for studying probiotics’ mode of action, from large scale screening, to molecular techniques focusing on single molecules and genome comparisons between strains.
  • Whether we need to apply something similar to Koch’s postulates when talking about the effects of probiotics.
  • The potential effects of food or delivery matrix on a probiotic mechanism of action.  
  • What we can learn from the postbiotic research, which can help inform probiotic mechanisms of action.
  • The most exciting developments in probiotic mode of action research in the past 10 years and the future of this area of research.

 

Episode links:

The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic
Prof. Marco refers to two of her mentors, Willem De Vos and Michiel Kleerebezem
See this overview of Koch’s postulates

 

Additional resources:

Bacterial genes lead researchers to discover a new way that lactic acid bacteria can make energy and thrive in their environments, ISAPP blog post featuring recent work from Prof. Marco’s lab

 

About Prof. Maria Marco:

Maria Marco is a Professor in the Department of Food Science and Technology and Chair of the Food Science Graduate Group at the University of California, Davis. She received her PhD in microbiology from the University of California, Berkeley and then was a postdoc and project leader at NIZO Food Research, The Netherlands. Dr. Marco has 20 years’ experience investigating fermented foods, probiotics, and diet-dependent, host-microbe interactions in digestive tract. Her laboratory at UC Davis is broadly engaged in the study of food and intestinal microbiomes and the ecology and genetics of lactic acid bacteria. 

Episode 1: The science of fermented foods, part 1

/in Podcast, Season One /by KC

Podcast: Play in new window | Download

Subscribe: Apple Podcasts | Spotify | RSS

The Science, Microbes & Health Podcast 

This podcast covers emerging topics and challenges in the science of probiotics, prebiotics, synbiotics, postbiotics and fermented foods. This is the podcast of The International Scientific Association for Probiotics and Prebiotic (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

The science of fermented foods, part 1, with Prof. Bob Hutkins

Episode summary:

The hosts discuss fermented foods with Prof. Bob Hutkins, University of Nebraska – Lincoln. Prof. Hutkins wrote a popular textbook on fermented foods and has had a 40-year career in fermentation science. He shares why he ended up in fermentation science, as well as how fermented foods are made and how important live microbes are for their health benefits.

Key topics from this episode:

  • What fermented foods are
  • The scientific consensus definition published by ISAPP
  • Fermentation processes and practices used in early times and still used today
  • The benefits and safety of fermented foods, as well as the difference between fermentation and food spoilage
  • The live microbes present in fermented foods, how many are present, and their potential health benefits
  • Why some fermented foods have live microbes and others do not; and how even when live microbes are absent due to heat treatment, for example, these products may still be classified as fermented 
  • The differences between fermented foods, probiotics, and probiotic fermented foods

 

Episode links:

Microbiology and Technology of Fermented Foods, 2nd Ed., by Robert W. Hutkins
The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods
The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic
Synbiotics: Definitions, Characterization, and Assessment – ISAPP webinar featuring Prof. Bob Hutkins and Prof. Kelly Swanson

 

Additional resources:

Fermented foods. ISAPP infographic
What are fermented foods? ISAPP video
Do fermented foods contain probiotics? ISAPP blog post
How are probiotic foods and fermented foods different? ISAPP infographic
Are fermented foods probiotics? Webinar by Mary Ellen Sanders, PhD

 

About Prof. Bob Hutkins:

Bob Hutkins is the Khem Shahani Professor of Food Microbiology at the University of Nebraska. He received his Ph.D. from the University of Minnesota and was a postdoctoral fellow at Boston University School of Medicine. Prior to joining the University of Nebraska, he was a research scientist at Sanofi Bio Ingredients.

The Hutkins Lab studies bacteria important in human health and in fermented foods. His group is particularly interested in understanding factors affecting persistence and colonization of probiotic bacteria in the gastrointestinal tract and how prebiotics shift the intestinal microbiota and metabolic activities. The lab also conducts clinical studies using combinations of pro- and prebiotics (synbiotics) to enhance health outcomes. More recently we have developed metagenome-based models that can be used in personalized nutrition.

Professor Hutkins has published widely on probiotics, prebiotics, and fermented foods and is the author of the recently published 2nd edition of Microbiology and Technology of Fermented Foods.

Do fermented foods contain probiotics?

/in Consumer Blog, ISAPP Science Blog /by KC

By Prof. Maria Marco, PhD, Department of Food Science & Technology, University of California, Davis

We frequently hear that “fermented foods are rich in beneficial probiotics.” But is this actually true? Do fermented foods contain probiotics?

The quick answer to this question is no – fermented foods are generally not sources of probiotics. Despite the popular assertion to the contrary, very few fermented foods contain microbes that fit the criteria to be called probiotic. But this fact does not mean that fermented foods are bad for you. To uphold the intent of the word probiotic and to explain how fermented foods actually are healthy, we need to find better ways to describe the benefits of fermented foods.

Probiotics are living microorganisms, that when administered in adequate amounts, confer a health benefit on the host (Hill et al 2014 Nat Rev Gastroenterol Hepatol). This current definition reflects minor updates to a definition offered by an expert consultation of scientists in 2001 convened by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization. Evident from the definition, a microbial strain is not a probiotic unless a health benefit has been found with its use. At a minimum, the strain should be proven to be beneficial in at least one randomized controlled trial (RCT). Probiotics must also be defined at the strain level through genome sequencing (a strain is a single genotype of a species).

Fermented foods, on the other hand, have no requirement to improve health. Fermented foods are foods and beverages made through desired microbial growth and enzymatic conversion of food components. This definition was recently formulated by an ISAPP consensus panel of scientific experts to affirm the common properties of all foods of this type and to differentiate foods that may look or taste similar but are not made using microbes (Marco et al 2021 Nat Rev Gastroenterol Hepatol). Fermented foods encompass an expansive variety of foods made from animal and plant sourced ingredients and produced from all types of microbial metabolism. The desired characteristics of these foods are frequently how they look, smell, and taste. There no expectation in this definition that fermented foods alter health in any way.

There is also no requirement for fermented foods contain living microbes at the time they are ingested. Foods such as bread, chocolate, and beer are fermented but then are baked, roasted, and/or filtered. This means those fermented foods cannot be probiotic.

Some fermented foods, such as kimchi and kombucha, are typically eaten with living microbes present. However, the microbes in those foods usually do not meet the criteria to be called probiotic. Whether the fermented food was made at home or purchased from the supermarket, studies investigating whether the microbes in those fermented foods are specifically responsible for a health benefit remain to be done. Those foods also do not contain microbes defined to the strain level, nor is the number of living microbes typically known. An exception to this is if specific strains previously shown to provide a health benefit in one or more RCT are intentionally used in the production of the food and remain viable at expected numbers over the shelf-life of that fermented food product. An example of this would be a commercial fermented yogurt that has an added probiotic strain remaining viable at the time of consumption, beyond the strains that carried out the fermentation.

Despite these distinctions between probiotics an fermented foods, the probiotics term has pervaded common lexicon to mean “beneficial microbes”. In contrast to pathogenic or harmful microbes, beneficial microbes are those that are understood to help rather than hurt bodily functions. However, just as we do not assume that all pathogens cause the same disease or result in the same severity of symptoms, we should also not expect that beneficial microbes all serve the same purpose. By analogy, automobiles are useful vehicles which help us to get from place to place. We do not expect that all automobiles perform like those used for Formula 1 racing. Microbes are needed to make fermented foods and may be beneficial for us, but we should not assume that those drive health benefits like established probiotic strains.

What are the consequences of calling fermented foods probiotic when they include undefined numbers of living microbes for which strain identities are not known? One can suppose that there is no harm in labeling or describing those products as “probiotic” or “containing probiotics”. However, by doing so, confusion and misunderstanding is created and too often, spread by journalists, nutritionists, scientists, and medical professionals. For example, news articles in reputable sources have written that foods like kefir, kimchi, sauerkraut made from beets or cabbage, pickles, cottage cheese, olives, bread and chocolate are rich in probiotics. As misuse perpetuates, what becomes of bona fide probiotics shown with rigorous study to benefit health, such as reducing the incidence and duration of diarrhea or respiratory infections? It becomes difficult to know which strains have scientific proof of benefit. Just as there are laws for standards of food identity, we should strive to do the same when describing microbes in fermented foods.

Avoiding the term probiotic when describing fermented foods should not stop us from espousing the myriad of positive attributes of those foods. Besides their favorable sensory qualities, fermented foods are frequently safer and better tolerated in the digestive tract than the foods they are made from. During the production of fermented foods, microbes remove or reduce toxins in the ingredients and produce bioactive compounds that persist long after the microbes that make them are gone.

Even though the living microbes in fermented foods may not rise to the standard of a probiotic, they may provide health benefits. We just don’t have the studies to prove that they do. With more study, we may find that viable microbes in fermented foods work similarly to probiotics in the digestive tract through shared mechanisms. This is already known for yogurts. Yogurt cultures share the ability to deliver lactase to the intestine, thereby improving tolerance of lactose by intolerant individuals. Clinical and epidemiological studies performed on fermented foods already suggest an association between them and different health benefits but as we recently explained (Marco et al 2021 J Nutrition), more work is needed in order to understand if and what benefits these microbes provide.

For now, we should simply continue enjoying the making and eating of fermented foods and reserve the term probiotics for those specific microbial strains which have been shown to improve our health. Marketers should resist labeling products as containing probiotics if their products do not meet the criteria for a probiotic. Indeed, the descriptor “live and active cultures” more accurately reflects the microbial composition of many fermented foods, and should be used until controlled human trials demonstrating health benefits are conducted.

 

Additional resources:

How are probiotic foods and fermented foods different? ISAPP infographic.

Fermented foods. ISAPP infographic.

What are fermented foods? ISAPP video.

Are fermented foods probiotics? Webinar by Mary Ellen Sanders, PhD.

 

ISAPP board members give a scientific overview of synbiotics in webinar

/in Consumer Blog, ISAPP Science Blog /by KC

Many kinds of products are labeled as synbiotics – but how do they differ from each other? And do they all meet the scientific criteria for synbiotic ingredients?

To demystify the science of synbiotics – including ISAPP’s definition published in 2020 – ISAPP is holding a free webinar: Synbiotics: Definitions, Characterization, and Assessment. Two ISAPP board members, Profs. Bob Hutkins and Kelly Swanson, present on the implications of the synbiotic definition for science and industry. They clarify the difference between ‘complementary’ and ‘synergistic’ synbiotics and cover the basics of meeting the criteria for synbiotic efficacy and safety. One challenge is learning when a synbiotic is required to have demonstrated both selective utilization of the microbiota in the same study that measures the health outcome. A Q&A is scheduled for the last 20 minutes of the webinar.

This webinar is for scientists, members of the public, and media who want a scientific overview on synbiotics as they appear in more and more consumer products.

The live webinar was broadcast on Friday, January 28th, 2022, from 10:00 am – 11:10 New York (Eastern) time.

Find the webinar recording here.

Research on the microbiome and health benefits of fermented foods – a 40 year perspective

/in Consumer Blog, ISAPP Science Blog /by KC

By Prof. Bob Hutkins, PhD, University of Nebraska Lincoln, USA

Many ISAPPers remember when fermented foods attracted hardly any serious attention from scientists outside the field. Certainly, most clinicians and health professionals gave little notice to fermented foods. In the decades before there were artisan bakeries and microbreweries proliferating on Main Street USA, even consumers did not seem very interested in fermented foods.

When I began my graduate program at the University of Minnesota in 1980, I was very interested in microbiology, but I did not know a lot about fermented foods. Accordingly, I was offered two possible research projects. One involved growing flasks of Staphylococcus aureus, concentrating the enterotoxins, feeding that material to lab animals, and then waiting for the emetic response.

My other option was to study how the yogurt bacterium, Streptococcus thermophilus, metabolized lactose in milk. This was the easiest career choice ever, and the rest, as they say, is history.

Indeed, that lab at Minnesota was one of only a handful in North America that conducted research on the physiology, ecology, and genetics of microbes important in fermented foods. Of the few labs in North America delving into fermented foods, most emphasized dairy fermentations, although some studied vegetable, meat, beer, wine, and bread fermentations. Globally, labs in Europe, Japan, Korea, Australia, and New Zealand were more engaged in fermented foods research than we were in North America, but overall, the field did not draw high numbers of interested researchers or students.

That’s not to say there weren’t exciting and important research discoveries occurring. Most research at that time was focused on the relevant functional properties of the microbes. This included carbohydrate and protein metabolism, flavor and texture development, tolerance to acid and salt, bacteriocin production, and bacteriophage resistance. Despite their importance, even fewer labs studied yeasts and molds, and the focus was on lactic acid bacteria.

Other researchers were more interested in the health benefits of fermented foods. Again, yogurt and other cultured dairy foods attracted the most interest. According to PubMed, there were about 70 randomized clinical trials (RCTs) with yogurt as the intervention between 1981 and 2001. Over the next 20 years, there were more than 400 yogurt RCTs.

Fast forward a generation or two to 2021, and now fermented foods and beverages are all the rage. Certainly, having the molecular tools to sequence genomes and interrogate entire microbiomes of these foods has contributed to this new-found interest. Scanning the recent literature, there are dozens of published papers on microbiomes (and metabolomes) of dozens of fermented foods, including kombucha (and their associated symbiotic cultures of bacteria and yeast, known as SCOBYs), kefir, kimchi, beer (and barrels), cheese (and cheese rinds), wine, vinegar, miso and soy sauce, and dry fermented sausage.

It’s not just fermentation researchers who are interested in fermented foods. For ecologists and systems biologists, fermented foods serve as model systems to understand succession and community dynamics and how different groups of bacteria, yeast, and mold compete for resources.

Moreover, consumers can benefit when companies that manufacture fermented foods take advantage of these tools. The data obtained from fermented food microbiota analyses can help to correlate microbiome composition to quality attributes or identify potential sources of contamination.

Importantly, it is also now possible to screen microbiomes of fermented foods for gene clusters that encode potential health traits. Indeed, in addition to microbiome analyses of fermented foods, assessing their health benefits is now driving much of the research wave.

As mentioned above, more than 400 yogurt RCTs were published in the past two decades, but alas, there were far fewer RCTs reported for other fermented foods. This situation, however, is already changing. The widely reported fiber and fermented foods clinical trial led by Stanford researchers was published in Cell earlier this year and showed both microbiome and immune effects. Other RCTs are now in various stages, according to clinicaltrials.gov.

Twenty years ago, when ISAPP was formed, I suspect few of us would have imagined that the science of fermented foods would be an ISAPP priority. If you need proof that it is, look no further than the 2021 consensus paper on fermented foods. It remains one of the most highly viewed papers published by Nature Reviews Gastroenterology and Hepatology.

Further evidence of the broad interest in fermented foods was the recently held inaugural meeting of The Fermentation Association. Participants included members of the fermented foods industry, culture suppliers, nutritionists, chefs, food writers, journalists, retailers, scientists and researchers.

Several ISAPP board members also presented seminars, including this one who remains very happy to have made a career of studying fermented foods rather than the emetic response of microbial toxins.

Pharmacists as influencers of probiotic use

/in ISAPP Science Blog /by KC

By Kristina Campbell, science writer

It’s not an uncommon scene in a pharmacy: someone standing in front of the shelf of probiotic products, picking up various bottles and reading the labels, looking uncertain. The person’s doctor may have recommended a certain brand of probiotic to prevent diarrhea with a prescribed course of antibiotics—but they’ve just noticed that the store-brand probiotic, with different strains, is half the price.

Dragana Skokovic-Sunjic

According to Dragana Skokovic-Sunjic, clinical pharmacist and author of the ‘Clinical Guide to Probiotic Products Available in Canada/US’, pharmacists can play an important and influential role helping patients make informed decisions about the available products. “Pharmacists provide a ‘last check validation’ before the patient actually decides to purchase a product,” she says. “And we proactively seek to assist those patients who need help.”

Nardine Nakhla

Nardine Nakhla, clinical pharmacist and Clinical Lecturer at the University of Waterloo School of Pharmacy, says pharmacists often have the knowledge and experience to zero in on which over-the-counter product(s) will or will not work for a certain individual. “Pharmacists have the knowledge and skills to individualize the recommendation based on patient-specific and disease-specific factors, and that is so very important with non-prescription and natural health products because there is no one-size-fits-all approach,” she says.

Can pharmacists apply their knowledge and skills to make specific probiotic recommendations? While it can be hard to narrow the evidence down on specific products, pharmacists can certainly play a role in helping patients understand the evidence for the products they encounter. In a recent interview with ISAPP, Skokovic-Sunjic and Nakhla explained why pharmacists in Canada and elsewhere have the potential to steer people’s choice of over-the-counter and natural health products – including probiotics.

Pharmacists have knowledge about the products on their shelves.

“Advising patients on self-care, which includes over-the-counter and natural health product use, is a key responsibility of Canadian pharmacists. We have North American survey data that shows, for patients who go out and buy non-prescription and natural health products, over 80% never read the label,” says Nakhla.

This means that having a pharmacist available at the point-of-purchase to answer questions can go a long way toward educating people about what’s actually in their hands and how to optimize use, if warranted.

“Having the pharmacist present lets you access somebody who can help inform your decisions—someone who can perhaps steer you away from products that may not be appropriate for you,” she says.

“Pharmacists need to be familiar with the products they are selling at their pharmacies,” adds Skokovic-Sunjic. “They are skilled at asking suitable questions to ensure the patient’s needs and wishes are understood and then to help them choose appropriate over-the-counter, ‘self-selection’ therapy.”

Pharmacists are unique in having non-prescription products within their standards of practice.

As a faculty member at the school of pharmacy, Nakhla emphasizes the requirement for pharmacists to know how to assess and manage patients seeking self-care in the community. She says, “We have a unique body of knowledge where we study non-prescription therapeutics and other self-care measures of disease management and health maintenance,” she says. “Pharmacists are trained to know about these and to recommend evidence-based and cost-effective measures individualized for each patient.”

“It’s explicitly stated under our Standards of Practice that we must be proficient in providing information on non-prescription products, natural health products, and on non-pharmacological measures to enable patients to receive the intended benefit of the therapies, whereas physicians are far more focused on the diagnosis and prescription therapies,” she says.

Pharmacists can identify patients who could benefit from probiotics

Both Nakhla and Skokovic-Sunjic emphasize that pharmacists frequently identify people who could potentially benefit from self-care products, even if they don’t come in looking for them.

Nakhla mentions the probiotic guide authored by Skokovic-Sunjic, and how it helps pharmacists provide helpful solutions to common problems that present in the community. “I think a good strategy is looking at the conditions listed in the probiotic guide and the subsequent products indicated for use for them, and then work backwards to try to identify patients who may benefit from the listed therapies, rather than just wait for them to present asking you questions.”

Pharmacists are in a position to encourage prevention.

“Pharmacy has historically focused on providing reactive healthcare rather than proactive or preventative care,” says Nakhla. But this has recently changed, with a growing emphasis on preventing chronic disease through ongoing health maintenance and self-care strategies. She cites pharmacists as qualified health professionals who encounter many generally healthy people throughout the course of their day, and who are therefore well-positioned to advise the public on how to remain healthy.

Skokovic-Sunjic gives some examples: “If the consumer will be travelling, we might suggest a specific probiotic to prevent traveller’s diarrhea. Or if we are coming to the cold and flu season, we may recommend a product they can take to reduce the risk of developing common infectious diseases.”

Pharmacists can conduct brief or lengthy assessments before providing recommendations.

Skokovic-Sunjic says, “A pharmacist can provide specific recommendations that could really make a big difference in the patient’s experience by quickly asking a few targeted questions. This strategy may save the patient time, money, frustration and sub-optimal health outcomes. When consumers self-select inappropriate products, they will not experience benefits they seek. Determined to choose a natural product, some consumers will try a second or even third product but will not get the symptom relief they are looking for. An unintended consequence of this is that the patient may dismiss the probiotics as ineffective not because they did not work, but because it was the wrong product for the desired effect.”

Brief assessment questions are especially important for probiotics, she adds, because specificity can ‘make or break’ how useful they are to an individual. “In my consultations with patients, I quite often include questions about bowel movements and I know they are questioning why I am asking. Understanding gut function can be extremely helpful in providing appropriate probiotic recommendations.”

Pharmacists can help people understand the concept of ‘evidence-based’.

Nakhla acknowledges it’s difficult for the average person to confront a shelf of probiotic products and delineate between the ones that have evidence backing their use, and the ones that do not. “That’s where I really think a pharmacist needs to intervene and to help them balance out the pros and the cons,” she says.

“If patients are looking for a probiotic to relieve a specific symptom, then looking for an evidence-based recommendation for that specific symptom is needed,” says Skokovic-Sunjic. “If they pick something that’s not supported by evidence, it may not provide symptom relief or the benefit they expect. This may be in addition to wasted funds and mounting frustration.”

Thus, pharmacists are in a unique position to contribute to enhanced awareness about efficacy and “evidence-based self-care” as they explain these concepts to consumers at the point of sale.

 

Given all the potential ways for pharmacists to guide consumer decisions about probiotics, both Skokovic-Sunjic and Nakhla agree that keeping up on the latest probiotic evidence is of high importance.

Through ISAPP’s new efforts to engage with pharmacists, the organization plans to gauge how pharmacists in various parts of the world approach probiotic recommendations, and to support the ‘best case scenario’ of pharmacists providing evidence-based information about probiotics directly to consumers.

Sign up here for ISAPP’s newsletter for pharmacists.

What’s the evidence on ‘biotics’ for health? A summary from five ISAPP board members

/in Consumer Blog, ISAPP Science Blog /by KC

Evidence on the health benefits of gut-targeted ‘biotics’ – probiotics, prebiotics, synbiotics, and postbiotics – has greatly increased over the past two decades, but it can be difficult to sort through the thousands of studies that exist today to learn which of these ingredients are appropriate in which situations. At a recent World of Microbiome virtual conference, ISAPP board members participated in a panel that provided an overview of what we currently know about the health benefits of ‘biotics’ and how they are best used.

Here’s a summary of what the board members had to say:

Dr. Mary Ellen Sanders: Probiotics and fermented foods

  • Probiotics are “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”.
  • Unfortunately, published assessments of probiotic products available on the market show that these products often fall short of required evidence. For example, their labels may not adequately describe the contents (including genus / species / strain in the product); they may not guarantee the efficacious dose through the end of the shelf life.
  • Contrary to common belief, probiotics do not need to colonize in the target site (e.g. the gut), impact gut microbiota composition, be derived from humans, or be resistant to stomach acid and other gut secretions such as bile.
  • Fermented foods are those made “through desired microbial growth and enzymatic conversions of food components”. The recent increased interest in fermented foods may come from people’s increased awareness of the role of gut microbes in overall health, but it is important to note that we have little direct evidence that the transient effects of fermented food microbes on the gut microbiota actually lead to health benefits. With that said, observational studies suggest that consuming some traditional fermented foods is associated with improved health outcomes.

Prof. Dan Merenstein, MD: Probiotics – How do I know what to prescribe for adult health?

  • A (limited) survey showed that most dietary supplement probiotic products cannot be linked to evidence because they do not provide enough information to determine what evidence exists to support their use – especially strains in the product. However, there are some probiotic products that have robust evidence.
  • Should every adult take a probiotic? The best evidence supports probiotics for improved lactose digestion and for prevention of difficile infection. Probiotics have also been shown to prevent common illnesses; reduce the duration of gut symptoms; and perhaps even reduce antibiotic consumption.
  • Studies will reveal more about the microbiome and about how probiotics work, for whom and for what indications. As with diet, the answer will most likely not be same for each person.

Prof. Glenn Gibson: Prebiotics and Synbiotics

  • A prebiotic is “a substrate that is selectively utilized by host microorganisms conferring a health benefit”. Researchers can test these substances’ activity in various ways: batch cultures, micro batch cultures, metabolite analysis, molecular microbiology methods, CF gut models, with in vivo (e.g. human) studies being required. Prebiotics appear to have particular utility in elderly populations, and may be helpful in repressing infections, inflammation and allergies. They have also been researched in clinical states such as IBS, IBD, autism and obesity related issues (Gibson et al., 2017).
  • A synbiotic is “a mixture, comprising live microorganisms and substrate(s) selectively utilized by host microorganisms, that confers a health benefit on the host.” While more studies are needed to say precisely which are useful in which situations, synbiotics have shown promise for several aspects of health in adults (Swanson et al. 2020): surgical infections and complications, metabolic disorders (including T2DM and glycaemia), irritable bowel syndrome, Helicobacter pylori infection and atopic dermatitis.

Prof. Hania Szajewska, MD: Biotics for pediatric use

  • Beneficial effects of ‘biotics’ are possible in pediatrics, but each ‘biotic’ needs to be evaluated separately. High-quality research is essential.
  • It is important that we view the use of ‘biotics’ in the context of other things in a child’s life and other interventions.
  • Breast milk is the best option for feeding infants
  • If breastfeeding is not an option, infant formulae supplemented with probiotics and/or prebiotics and/or postbiotics are available on the market.
  • Pro-/pre-/synbiotic supplemented formulae evaluated so far seem safe with some favorable clinical effects possible, but the evidence is not robust enough overall to be able to recommend routine use of these formulae.
  • Evidence is convincing on probiotics for prevention of necrotizing enterocolitis in preterm infants.
  • Medical societies differ in their recommendations for probiotics to treat acute gastroenteritis in children – they appear beneficial but not essential.
  • Synbiotics are less studied, but early evidence indicates they may be useful for preventing sepsis in infants and preventing / treating allergy and atopic dermatitis in children.

Prof. Gabriel Vinderola: Postbiotics

  • The concept of non-viable microbes exerting a health benefit has been around for a while, but different terms were used for these ingredients. Creating a scientific consensus definition will improve communication with health professionals, industry, regulators, and the general public. It will allow clear criteria for what qualifies as a postbiotic, and allow better tracking of scientific papers for future systematic reviews and meta-analyses.
  • The ISAPP consensus definition (in press) of a postbiotic is: “A preparation of inanimate microorganisms and/or their components that confers a health benefit on the host”.
  • Postbiotics are stable, so no cold-chain is needed to deliver them to the consumer. Safety is of less concern because the microbes are not alive and thus cannot cause bacteraemia.
  • Research in the coming years will reveal more about postbiotics and the ways in which they can promote human health.

See here for the entire presentation on Biotics for Health.

Probiotics and fermented foods, by Dr. Mary Ellen Sanders (@1:15)

Postbiotics, by Prof. Gabriel Vinderola (@18:22)

Prebiotics and synbiotics, by Prof. Glenn Gibson (@33:24)

‘Biotics’ for pediatric use, by Prof. Hania Szajewska (@47:55 )

Probiotics: How do I know what to prescribe for adult health? by Prof. Dan Merenstein (@1:04:51)

Q&A (@1:20:00)

 

Probiotics in fridge

Designing Probiotic Clinical Trials: What Placebo Should I Use?

/in ISAPP Science Blog /by KC

By Daniel J. Merenstein, MD, Professor, Department of Family Medicine and Director of Research Programs, Georgetown University Medical Center, Washington DC

Specifying a placebo is one of the most important decisions for a clinical trialist. The first trial I led was a study giving Benadryl to kids to see if it helped them sleep. We spent hours working with our pharmacist on the placebo to make sure it had the same sweet cherry taste of the active drug, Benadryl. We didn’t want parents to be able to determine whether they were randomized to Benadryl or the placebo by comparing the study product to what they had at home. Do study subjects really do this? Yes. Early in my career I was helping an orthopedist who was putting pain pumps directly into a patient’s ankle post-surgery in order to see if it would decrease oral narcotic usage. One of our first patients pulled his pump out, tasted the medicine and called us late at night complaining he was in the saline (placebo) group.

When undertaking a study on probiotics, and specifically probiotic yogurts, we can debate for weeks about the best placebo. Our intervention is yogurt fortified with an additional probiotic. Therefore, our intervention yogurt contains both the starter lactic acid bacteria and the probiotic. So assuming we want both groups to get nutritionally equivalent yogurt that can be blinded our placebo options could be as follows. Note that in recent years, we have become more cognizant that dead microbes may not be biologically inactive.

Placebo Microbiological content of Placebo Research question addressed
Yogurt Live starter cultures, no probiotic What is the contribution of probiotics to any health benefit?
Acidified yogurt No live or dead microbes What is the contribution of live probiotic + live starter cultures to any health benefit?
Heat treated yogurt No live microbes, dead starter microbes Beyond any contribution of dead starter cultures, what is the contribution of live probiotic + live starter cultures to the health benefit?
Heat treated probiotic yogurt No live microbes, dead starter + dead probiotic microbes Beyond any contribution of dead probiotics + dead starter cultures, what is the contribution of live probiotic + live starter cultures to the health benefit?
Probiotic yogurt using a different probiotic Live starter cultures, live probiotic different from the probiotic in the intervention What is the contribution of the intervention probiotic to any health benefit compared to the control probiotic?

 

We chose regular yogurt (the first option above) and now about eight papers later, I would say that about 50% of reviewers question our choice.

There are many reasons the placebo needs to be well considered, including the specific research question under consideration. But an important one is clinical equipoise, “a state of genuine uncertainty on the part of the clinical investigator regarding the comparative therapeutic merits of each arm in a trial”, as defined Freedman 1987. Thus, for example in a study of a new hypertension drug, one cannot use a placebo that has no chance of lowering a patient’s blood pressure as a comparator as that is ethically indefensible. Instead, a well proven hypertension drug will be studied versus the new experimental drug.

For most of my career the goal in my studies was to pick a placebo that was as inactive as possible that still smelled, looked and tasted like my active intervention. However, the times are changing. When I started working there were fewer than 200 randomized controlled clinical probiotic trials retrievable from PubMed; today the number is over 2,300. Well that means we have gone beyond merely recognizing the value of probiotics in different indications, to detailed comparisons of different probiotic and non-probiotic interventions, so one has to consider how inactive their placebo is for probiotic intervention trials.

In 2020 the American Gastrointestinal Association came out with recommendations and guidelines after they conducted a thorough review of probiotic evidence. (See ISAPP blog ISAPP take-home points from American Gastroenterological Association guidelines on probiotic use for gastrointestinal disorders.) For three indications, they recommended using select probiotics over no or other probiotics, in populations of preterm low birthweight infants, patients receiving antibiotics, and patients with pouchitis. So what does this mean for trials evaluating one of these indications? It means that the placebo should be an active control, a probiotic versus probiotic trial.

Today if I’m asked what placebo should be used, my first question is what indication are you studying? If you are studying infant colic or preterm low birthweight infants, I think you need an active control, such as another probiotic. (Colleagues and I suggested this for probiotic studies on necrotizing enterocolitis in 2013.) If you are studying anxiety, then an inert placebo makes the most sense since insufficient evidence exists for any probiotic for this endpoint as yet. In the case of antibiotic associated diarrhea, it will be a much longer discussion as the data are not clear, but it would be reasonable for an IRB to argue that your placebo should be another probiotic. It is not ethical to deny a placebo group an effective intervention if one is available.

So in the last 15 years of my career the answer to what placebo should I use has greatly changed. As probiotic research has advanced, so has the evidence base for usage. As we proceed with research we now need to consider conducting our clinical trials differently. This is just another example of how probiotic evidence has matured over a relatively short period of time.

ISAPP board members look back in time to respond to Benjamin Franklin’s suggestion on how to improve “natural discharges of wind from our bodies”

/in News, Consumer Blog /by KC

Benjamin Franklin, born in 1706, was a multi-talented politician and scientist best known for his discoveries related to electricity. Historians say he was scientifically pragmatic—aiming not just to advance theories, but to solve the most vexing problems of the day.

In 1780, when Franklin read about the intellectual contests being held by The Royal Academy of Brussels (today known as the Royal Flemish Academy of Belgium for Science and the Arts – KVAB), he took it upon himself to write an amusing letter that contained a suggestion for an important scientific challenge: “To discover some Drug wholesome & not disagreable, to be mix’d with our common Food, or Sauces, that shall render the natural Discharges of Wind from our Bodies, not only inoffensive, but agreable as Perfumes.”

Over two centuries later, the organization was prompted for a reply. Writer Brian Van Hooker wrote to the KVAB: ‘I am a writer at MEL Magazine and I am working on a piece about a letter that Benjamin Franklin sent to your organization’s predecessor, the Royal Academy of Brussels, 240 years ago. The letter was entitled “Fart Proudly,” and I’m reaching out to see if anyone at your organization might like to issue a reply to Mr. Franklin’s letter’.

Since ISAPP board member Prof. Sarah Lebeer (University of Antwerp, Belgium) is a KVAB Belgian Young Academy alumna with microbiome knowledge, Bert Seghers from the Academy asked her to help draft a reply. However, since the gut microbiome is not her main area of expertise, she consulted her fellow ISAPP board members. For example, Bob Hutkins, author of a popular ISAPP blog post on intestinal gas, immediately sent her a paper entitled Identification of gases responsible for the odour of human flatus and evaluation of a device purported to reduce this odour with the comment: “The next time a graduate student complains about their project, refer them to this paper and the 5th paragraph of the methods”—a paragraph that describes how scientists in the experiment were tasked with rating the odor of flatus and differentiating between the different smells of sulphur-containing gases.

But it was the answer of Prof. Glenn Gibson (University of Reading, UK) that was incorporated into the ‘formal’ reply to Franklin’s suggestion. “Your suggested topic on improving flatulence odour is amusing, but indeed also very relevant. An outstanding answer to the contest as you formulate it would be ground-breaking,” wrote Profs. Lebeer and Gibson. They noted that gases in the intestine are mainly released by the bacteria living there—but especially the sulphate reducing bacteria contribute to the “traditional” smell due to their production of noxious H2S —and that advances in probiotic and prebiotic science could one day lead to reduced (and “nicer smelling”) gas production by switching hydrogen gas production to methane or even acetate and away from H2S.

Brian Van Hooker summarized: “In other words, Mr. Franklin, they’re working on it and, perhaps sometime within the next 240 years, your dream of non-smelly farts might just come true.”

The KVAB response to Benjamin Franklin concluded: “Your letter is a ripple through time. It may not surprise you that scientific questions can have effects across decades and even centuries. This idea remains the tacit hope of many scientists working together for the progress of humanity. We have not yet invented a reverse time machine, but we send our answer along with your question forward in time, hoping that it may inspire future scientists as your question inspired us.”

Read the MEL Magazine article here.

Read more about gut microbiota & intestinal gas here.

New Spanish-language e-book about fermented foods now available for download

/in News, Consumer Blog /by KC

By Dr. Gabriel Vinderola, PhD,  Associate Professor of Microbiology at the Faculty of Chemical Engineering from the National University of Litoral and Principal Researcher from CONICET at Dairy Products Institute (CONICET-UNL), Santa Fe, Argentina

Fermented foods and beverages such as yogurt, wine, beer, kefir, kombucha, kimchi, and miso are created with the help of microbes. After more than 10,000 years of practice around the globe, fermentation has finally caught massive attention from a general public interested in knowing more about the fascinating, invisible world of microbes. In essence, the act of fermentation places food in a unique place between raw and cooked. The flavours, tastes, textures and potential health benefits of fermented foods, made possible through the presence of viable or non-viable microbes and their metabolites, are achieved through this set of ancestral food processing techniques. Today’s science allows us to see the functions of fermentation microbes that can make certain nutrients more bioavailable in foods. Fermentation can also reduce certain anti-nutrients and generate a large number of potentially beneficial microorganisms.

To help people learn about fermented foods, I was pleased to collaborate on an e-book with Ricardo Weill, an Argentinian dairy industry expert who first introduced Lactobacillus rhamnosus GG in Argentinian fermented milks in the 1990s, and Alejandro Ferrari, a biologist and scientific communications expert. The book is titled ‘Fermented Foods: microbiology, nutrition, health and culture’, and is currently available only in Spanish.

The book aimed to reach the general public, with scientific concepts but in easy-to-follow language for people with little or no previous knowledge of microbiology, nutrition or food technology. It tells the stories of many types of fermented foods around the world and adds a scientific perspective on their health benefits. The book brings together information from 38 authors from Argentina, Colombia, Japan, Spain and Finland, including ISAPP President Prof. Seppo Salminen, and Martin Russo, a professional chef in Argentina who specializes in fermentation. The book includes the following sections:

Fermentation: An anthropological view

Variety of fermented foods in Japan and other East Asian countries, and the microorganisms involved in their fermentation

Introduction to the intestinal microbiota: its role in health and the disease

Consumption of probiotic fermented milk and its impact on the immune system

Fermented milks, yogurts and probiotics

Kefir and artisanal fermented foods

Fermented meat sausages: Contribution of lactic bacteria in global quality

Lactic fermentation of cereals and Andean ancestral grains

Fermented vegetables and legumes

Fermentation of fruit drinks and drinks

Yeasts in beer and baked goods

Role of fermented foods in diet

Role of lactic acid in the beneficial effects of fermented foods

Microbiological safety of fermented foods

Fermented foods and chronic non-communicable diseases: A narrative review of the literature

Fermentation and gastronomy: A cook among scientists, a scientist among cooks

This e-book initiative started in October 2019, when a symposium about fermented food was organized by the Danone Institute of the Southern Cone (DISC).

The Danone Institute of the Southern Cone (DISC) was founded in 2008, and it is the local chapter for Argentina, Chile and Uruguay of the Danone Institute International network, which gathers 14 Danone Institutes (13 local Institutes and 1 International) in 15 countries. All Danone Institutes are non-profit organizations, dedicated to non-commercial activities and promotion of science.

Since its foundation, the DISC has collaborated with more than 200 experts taking part in different projects, and has served as a collaborative meeting place to reflect with their peers—all of them remarkable scientists coming from different and complementary specialties, focusing on key aspects of public health linked to food.

See the link to our book here:

Fermented Food: Microbiology, Nutrition, Health & Culture. (2020)

See the ISAPP press release about this book in English and en español.

Some previously-produced nutrition books that are freely available in Spanish on the DISC website are:

  • Impact of Growth and Early Development on the Population’s Health and Wellbeing. Perspectives and Reflections from the Southern Cone. (2009)
  • Healthy Growth. Between Malnutrition and Obesity in the Southern Cone. (2011)
  • The Role of Calcium and Vitamin D in Bone Health and Beyond. Perspective from the Southern Cone. (2013)
  • Methodologies Employed in Food Evaluation. An Ibero-American Vision. (2015)
  • Their Impact in Nutrition and Health. A Vision from the Southern Cone. (2018)

Current status of research on probiotic and prebiotic mechanisms of action

/in ISAPP Science Blog /by KC

By Mary Ellen Sanders, PhD, ISAPP Executive Science Officer

Human intervention studies in the fields of probiotics and prebiotics assess the health effects of these ingredients, whether it’s improving specific symptoms or preventing the occurrence of a health condition. Yet scientists in the field recognize the importance of learning the ‘chain of events’ by which probiotics and prebiotics are able to confer health benefits. Such mechanistic insights allow better probiotic selection and development of therapeutic approaches, as well as more precise dosing.

Mechanisms of action for probiotics and prebiotics are complex and often difficult to pinpoint, especially since any given health benefit may derive from multiple co-functioning mechanisms. However, scientists have made incremental gains in understanding these mechanisms. This scientific progress was covered in a recent webinar co-presented by ISAPP and ILSI-Europe, titled Understanding Prebiotic and Probiotic Mechanisms that Drive Health Benefits. Speakers for the webinar were:

  • Sarah Lebeer, University of Antwerp, Belgium
  • Colin Hill, University College Cork, Ireland
  • Karen Scott, University of Aberdeen, UK
  • Koen Venema, Maastricht University – campus Venlo, The Netherlands

The webinar was held live on September 17, 2020. Of the 499 webinar registrants, 357 attended the webinar live from 57 countries, from Australia to the US. ISAPP and ILSI-Europe hope the webinar will serve as a resource for people who want a rapid overview about mechanisms of action.

Watch the full webinar here, and read further for a summary of key points from these experts.

Prebiotic benefits and mechanisms of action

Prebiotics are defined as substrates that are “selectively utilized by host microorganisms conferring a health benefit”. ‘Utilization’ in the gut may involve crossfeeding, which means products produced by the first microbes degrading the prebiotic can then be used by different members of the host microbiota – so it may take a series of complex steps to get to a final health outcome. However, selective utilization and health benefit are always required for a substance to meet the definition of a prebiotic.

The health benefit of a prebiotic can be local (in the gut) or systemic. Locally, prebiotics can act via fecal bulking, as they are typically types of fiber. In addition, they can produce short-chain fatty acids (SCFAs), which reduce gut pH and thereby can discourage pathogenic and toxigenic activity of gut microbes, increase calcium ion absorption and provide energy for gut epithelial cells.

Systemic functions of prebiotic metabolism include them being used as substrates for microbes that produce or interact with host cells to produce molecules with neurochemical, metabolic or immune activity. Further, SCFAs can end up in the blood and can reach the liver, muscles and the brain. The SCFAs interact with specific host receptors and can lead to the release of satiety hormones or interact with receptors in the liver, adipose tissue and muscle tissue, leading to reduced inflammation. Prebiotics can also interact directly with immune cells.

Probiotic health effects and mechanisms of action

Health and disease are the end results of complex interactions on a molecular scale within a human or animal host.  Host molecules also interact with microbial molecules, including those molecules introduced with or produced by probiotics. Designing studies to discover probiotic mechanisms in human research is extremely challenging because both host and probiotic are very complex systems that most probably engage with one another on multiple levels. Probiotic molecules can have direct effects and downstream effects, and we are aware of only a few cases where a health effect can be tied to one specific probiotic molecule.

Probiotics can interact directly with the host, but also can act indirectly by influencing the microbiome. There may be many different mechanisms by which a given probiotic interacts with the host.

It is interesting to note that probiotics use some of the same types of mechanisms (pili, small molecule production, etc.) that are used by pathogens, microbes that have a detrimental effect on the host.  But these shared mechanisms are usually connected to surviving or colonising strategies, not those that cause damage to the host.

L. rhamnosus GG is a well-researched model probiotic, for which many mechanisms have been identified, including pili, immune modulators and lactic acid production, some mechanisms shared with other probiotic strains and species. Other studies have identified mechanisms for novel types of probiotics. For example, in mice and humans taking a strain of Akkermansia, heat killed cells had the same or even better effect on markers of metabolic health, which implies that the molecules (perhaps proteins in the bacteria, unaffected by heat treatment) are mediating the effect in this case.

See here to watch the webinar in full.

 

 

60 Minutes’ 13 minutes on probiotics

/in ISAPP Science Blog /by KC

By Mary Ellen Sanders, PhD, ISAPP Executive Science Officer 

On June 28, 60 Minutes aired a 13-minute segment about probiotics titled, “Do Probiotics Actually Do Anything?” Unfortunately the media segment did not provide listeners with a nuanced perspective.

‘Probiotics’ were treated as if they were one entity, ignoring the best approach to addressing the topic of what probiotics do: evaluate the evidence for specific strains, doses and endpoints, and then make a conclusion based on the totality of the evidence. They would have found that many experts agree that actionable evidence exists for certain probiotics to prevent antibiotic associated diarrhea (here, here), prevent upper respiratory tract infections (here), prevent morbidity and mortality associated with necrotizing enterocolitis (here,), treat colic (here), and treat acute pediatric gastroenteritis (here). (For an overall view of evidence, see here.)

Importantly, not all retail probiotics have evidence (at least evidence that is readily retrievable, see here and here). But that does not mean that none do.

The 60 Minutes segment also highlighted questions about probiotic safety. No intervention is without risk, and no one claims as much for probiotics. Prof. Dan Merenstein, MD, just one clinical investigator of probiotics, has collected over 20,000 pediatric clinical patient days’ worth of safety data over the past eight years of clinical investigation, with no indication of safety concerns. In fact, participants in the placebo group generally have more adverse events than in the probiotic groups. But importantly, the safety standard for probiotics was mischaracterized by 60 Minutes. According to Dr. James Heimbach, a food safety expert (not interviewed in the segment) who has conducted 41 GRAS determinations on probiotics, over 25 of them notified to the FDA, he objects to the statement that GRAS is a lower safety bar than a drug. He clarifies:

“The safety standard that applies to food additives and GRAS substances, “reasonable certainty of no harm,” is a far higher standard than that applying to drugs. Drugs are judged against a risk/benefit standard, which can potentially allow quite dangerous drugs on the market provided they offer a significant benefit. The safety standard for drugs also applies only to prescribed doses for specific individuals over prescribed durations. The food-additive/GRAS substance standard, on the other hand, requires safety at any biologically plausible level of intake, for any person (child, adult, elderly; pregnant; etc.), over a lifetime. And it is a risk-only standard—no potential benefit is allowed to override the “reasonable certainty of no harm” standard. Additionally, in the case of GRAS substances (which includes most probiotics), the evidence of safety must be published in the peer-reviewed scientific literature and be widely accepted by the scientific community as well as by government regulators.”

Finally, the story implied that benefits people claim for themselves when using probiotics are due to a placebo effect. This ignores the many properly controlled studies directly comparing the effects of specific probiotics to placebos. A positive trial on probiotics, such as observed in this recent trial on irritable bowel syndrome symptoms (here) and in most trials included in Cochrane meta-analyses on prevention of C. difficile-associated diarrhea (here), means that positive effects were observed beyond any placebo effect. The placebo effect is real, equally applicable to probiotics and drugs, but as with all clinically evaluated substances, properly controlled trials control for this effect.

The probiotic field has come a long way over the past 20 years with regard to number and quality of clinical trials. In that time, well-done systematic reviews of the evidence have found benefits for specific probiotics for specific conditions, while also finding a lack of evidence for beneficial effects in other contexts. There are of course well-conducted clinical trials that have failed to demonstrate benefit (here, here, here). This should not be equated to mean that probiotics do not do anything.

Many challenges remain for improving the quality of the evidence across the wide range of different strains, doses, endpoints and populations. More clinical research needs to be conducted in a manner that minimizes bias and is reported according to established standards. Confidence in the quality of commercial products could be improved by industry adopting third party verification (here), and the quality of products targeting compromised populations need to be fit for purpose (here). Companies should stop using the term ‘probiotic’ on products that have no evidence warranting that description. We need to understand much better how a person’s individual situation, such as diet, microbiome, use of medications and fitness, impact the ability of a probiotic to promote health. Much remains to be learned in this evolving and exciting field. As Dr. Merenstein says, “The key question is not, ‘Do probiotics actually do anything?’, as that is easily answered ‘yes’ when you look at robust placebo-controlled trials of specific probiotics. Better questions are ‘Which probiotics do anything, and for what?’”

Further reading:

Misleading press about probiotics: ISAPP responses

ISAPP take-home points from American Gastroenterological Association guidelines on probiotic use for gastrointestinal disorders

New publication gives a rundown on probiotics for primary care physicians

Safety and efficacy of probiotics: Perspectives on JAMA viewpoint

ISAPP welcomes three new board members

/in News /by KC

By Mary Ellen Sanders, PhD, ISAPP Executive Science Officer

ISAPP is pleased to announce that Profs. Kelly Swanson PhD, Daniel Tancredi PhD, and Gabriel Vinderola PhD have joined the ISAPP board of directors. The expertise of these three globally recognized academic experts complements that of the current board members, together comprising a leading global group of distinguished scientific and clinical experts in the fields of probiotics, prebiotics, synbiotics, fermented foods, and postbiotics.

Read more about ISAPP’s newest board members:

Kelly Swanson is the Kraft Heinz Company Endowed Professor in Human Nutrition, a professor in the Department of Animal Sciences and Division of Nutritional Sciences and an adjunct professor in the Department of Veterinary Clinical Medicine at the University of Illinois at Urbana-Champaign. He is an expert in the field of fiber and prebiotics, and brings to ISAPP knowledge of application of these substances to companion and agricultural animals. Kelly, who trained with previous ISAPP Board member, George Fahey, is considered one of the top authorities in animal gut health, microbiome, and nutrition. His research has focused on testing the effects of nutritional intervention on health outcomes, identifying mechanisms by which nutrients impact gastrointestinal microbiota, host gene expression, and host physiology. Kelly served on the prebiotic consensus panel (here), led the ISAPP synbiotics consensus panel, and is lead author on the synbiotics outcome paper, currently in press with Nature Reviews Gastroenterology and Hepatology.

Dan Tancredi is a biostatistician with an appointment as an Associate Professor (full professor starting July 1, 2020) in Residence at UC Davis Department of Pediatrics, and is also with the Center for Healthcare Policy and Research. Dan works extensively on NIH-sponsored research and as an NIH scientific reviewer. He has an extensive record of collaboration with ISAPP; he has served as an invited expert and/or speaker at all but one ISAPP meeting since 2009, providing his perspectives on how to improve the quality and scientific impact of probiotic trials and how to conduct systematic reviews that rigorously and transparently synthesize the evidence from these trials. He has been a co-author on 6 ISAPP papers (here, here, here, here, here, here and here), including a 2020 paper “Probiotics as a Tx Resource in Primary Care” published in the Journal of Family Practice (see New publication gives a rundown on probiotics for primary care physicians). Dan was invited to author the Nature commentary on the landmark probiotics trial by Panigrahi, et al. for reducing newborn sepsis in the developing world—showing his reputation as a trusted voice for assessing the quality of probiotic research.

Gabriel Vinderola is a professor at National University of Litoral, Santa Fe, Argentina and Principal Researcher at CONICET, at the Dairy Products Institute (UNLCONICET). He is an expert in lactic acid bacteria, fermented foods, and probiotics. Gabriel has forged academic collaborations with academic and industrial scientists in numerous countries in Europe and with industrial colleagues in Argentina. He has been active in several countries in South America working with regulators to assure that their actions on probiotic guidelines are science-based, including his recent efforts consulting on guidelines for probiotics for the Codex Alimentarius. He has written blogs for ISAPP, translated ISAPP videos and infographics into Spanish, and was an expert on the ISAPP consensus panel on postbiotics. His research has focused on technological aspects of probiotics (biomass production, dehydration, storage, food matrices) and fermented foods. He is an active public science communicator in Argentina on the topics of probiotics, prebiotics, fermented foods, and the microbiome. See Growing interest in beneficial microbes and fermented foods in Argentina for some examples. Gabriel represents the first ISAPP board member from South America and we anticipate his involvement will help ISAPP expand its presence and connections in Latin America.

 

ISAPP partners with British Nutrition Foundation for fermented foods webinar

/in Consumer Blog, News /by KC

Did you miss the live webinar? Access the archived version here. Read the speaker Q&A here.

From sourdough starter tips to kombucha flavor combinations – if you’ve checked a social media feed lately, you’ll know how many people are sharing an interest in fermented foods as they self-isolate during the pandemic. And with this rise in popularity comes a host of questions about the practice and the science of fermented foods.

To meet the need for science-based information about fermented foods, ISAPP has partnered with the British Nutrition Foundation (BNF) on a free webinar titled ‘Fermented Food – Separating Hype from Facts.’ The BNF is a UK-based registered charity that brings evidence-based information on food and nutrition to all sectors, from academia to medicine.

The webinar, designed for practicing dietitians and nutrition-savvy members of the public, featured three leading scientific experts who explained the microbiology of fermented foods, the evidence for their health effects, and who might benefit from making these foods a regular part of the diet. Viewers will come away with a clear understanding of what fermented foods are and what evidence exists for their health benefits.

The webinar was held live on Wednesday, July 1, 2020 from 1pm-2pm (BST).

Webinar speakers & topics

 Understanding fermented foods: Dr. Robert Hutkins, University of Nebraska, USA

Exploring the evidence for effects of fermented foods on gastrointestinal health – how strong is it? Dr. Eirini Dimidi, Kings College London

What role can fermented foods have in our diet? A public health perspective, Anne de la Hunty, British Nutrition Foundation

For a quick primer on fermented foods, see the short ISAPP video here or the ISAPP infographic here.

ISAPP provides guidance on use of probiotics and prebiotics in time of COVID-19

/in ISAPP Science Blog, News /by KC

By ISAPP board of directors

Summary: No probiotics or prebiotics have been shown to prevent or treat COVID-19 or inhibit the growth of SARSCoV-2. We recommend placebo-controlled trials be conducted, which have been undertaken by some research groups. If being used in clinical practice in advance of such evidence, we recommend a registry be organized to collect data on interventions and outcomes.  

Many people active in the probiotic and prebiotic fields have been approached regarding their recommendations for using these interventions in an attempt to prevent or treat COVID-19. Here, the ISAPP board of directors provides some basic facts on this topic.

What is known. Some human trials have shown that specific probiotics can reduce the incidence and duration of common upper respiratory tract infections, especially in children (Hao et al. 2015; Luoto et al. 2014), but also with some evidence for adults (King et al. 2014) and nursing home residents (Van Puyenbroeck et al. 2012; Wang et al. 2018). However, not all evidence is of high quality and more trials are needed to confirm these findings, as well as determine the optimal strain(s), dosing regimens, time and duration of intervention. Further, we do not know how relevant these studies are for COVID-19, as the outcomes are for probiotic impact on upper respiratory tract infections, whereas COVID-19 is also a lower respiratory tract infection and inflammatory disease.

There is less information on the use of prebiotics for addressing respiratory issues than there is for probiotics, as they are used mainly to improve gut health. However, there is evidence supporting the use of galactans and fructans in infant formulae to reduce upper respiratory infections (Shahramian et al. 2018; Arslanoglu et al. 2008). A meta-analysis of synbiotics also showed promise in repressing respiratory infections (Chan et al. 2020).

Mechanistic underpinnings. Is there scientific evidence to suggest that probiotics or prebiotics could impact SARS-CoV-2? Data are very limited. Some laboratory studies have suggested that certain probiotics have anti-viral effects including against other forms of coronavirus (Chai et al. 2013). Other studies indicate the potential to interfere with the main host receptor of the SARS-CoV-2 virus, the angiotensin converting enzyme 2 (ACE2). For example, during milk fermentation, some lactobacilli have been shown to release peptides with high affinity for ACE (Li et al. 2019). Recently, Paenibacillus bacteria were shown to naturally produce carboxypeptidases homologous to ACE2 in structure and function (Minato et al. 2020). In mice, intranasal inoculation of Limosilactobacillus reuteri (formerly Lactobacillus reuteri) F275 (ATCC 23272) has been shown to have protective effects against lethal infection from a pneumonia virus of mice (PVM) (Garcia-Crespo et al. 2013). These data point towards immunomodulatory effects involving rapid, transient neutrophil recruitment in association with proinflammatory mediators but not Th1 cytokines. A recent study demonstrated that TLR4 signaling was crucial for the effects of preventive intranasal treatment with probiotic Lacticaseibacillus rhamnosus (formerly Lactobacillus rhamnosus) GG in a neonatal mouse model of influenza infection (Kumova et al., 2019). Whether these or other immunomodulatory effects, following local or oral administration, could be relevant to SARS-CoV-2 infections in humans is at present not known.

Our immune systems have evolved to respond to continual exposure to live microbes. Belkaid and Hand (2016) state: “The microbiota plays a fundamental role on the induction, training, and function of the host immune system. In return, the immune system has largely evolved as a means to maintain the symbiotic relationship of the host with these highly diverse and evolving microbes.” This suggests a mechanism whereby exposure to dietary microbes, including probiotics, could positively impact immune function (Sugimura et al. 2015; Jespersen et al. 2015).

The role of the gut in COVID-19. Many COVID-19 patients present with gastrointestinal symptoms and also suffer from sepsis that may originate in the gut. This could be an important element in the development and outcome of the disease. Though results from studies vary, it is evident that gastrointestinal symptoms, loss of taste, and diarrhea, in particular, can be features of the infection and may occur in the absence of overt respiratory symptoms. There is a suggestion that gastrointestinal symptoms are associated with a more severe disease course. Angiotensin converting enzyme 2 and virus nucleocapsid protein have been detected in gastrointestinal epithelial cells, and infectious virus particles have been isolated from feces. In some patients, viral RNA may be detectable in feces when nasopharyngeal samples are negative. The significance of these findings in terms of disease transmission is unknown but, in theory, do provide an opportunity for microbiome-modulating interventions that may have anti-viral effects (Cheung et al. 2020; Tian et al. 2020; Han et al. 2020).

A preprint (not peer reviewed) has recently been released, titled ‘Gut microbiota may underlie the predisposition of healthy individuals to COVID-19’ (Gao et al. 2020) suggesting that this could be an interesting research direction and worthy of further discussion. A review of China National Health Commission and National Administration of Traditional Chinese Medicine guidelines also suggested probiotic use, although more work on specific strains is needed (Mak et al. 2020).

Are probiotics or prebiotics safe? Currently marketed probiotics and prebiotics are available primarily as foods and food/dietary supplements, not as drugs to treat or prevent disease. Assuming they are manufactured in a manner consistent with applicable regulations, they should be safe for the generally healthy population and can be consumed during this time.

Baud et al. (in press) presented a case for probiotics and prebiotics to be part of the management of COVID-19. Although not fully aligned with ISAPP’s official position, readers may find the points made and references cited of interest.

Conclusion. We reiterate, currently no probiotics or prebiotics have been shown to prevent or treat COVID-19 or inhibit the growth of SARSCoV-2.

 

Connecting with the ISAPP community: Continuing to advance the science of probiotics and prebiotics

/in ISAPP Science Blog, News /by KC

By Mary Ellen Sanders PhD, executive science officer, ISAPP

On behalf of the ISAPP board of directors, I am reaching out to the ISAPP community to say we hope you are doing well and taking all the necessary steps in your local communities to remain healthy. At present, the global ISAPP community is physically distant but digitally close, and it is important for us to remain connected and strong.

ISAPP’s activities are as important as ever during this time of increased attention to health, and ISAPP is continuing to uphold its commitment to (1) stewardship, (2) advancing the science, and (3) working with stakeholders. Although our annual meeting, which some of you may have initially planned to attend, has been cancelled, other ISAPP activities are continuing or expanding as follows:

 

  • Building on an important topic for our annual meeting, ISAPP is working to develop a strategic approach to communicating the science on probiotics, prebiotics, fermented foods, synbiotics, and postbiotics.
  • The ISAPP board of directors is pleased that our founding board members, Profs. Gregor Reid and Glenn Gibson, have agreed to remain on the board until the 2021 meeting, in particular to help with long-range planning. New academic board members will also be elected, thereby expanding the board. Working together, we will bring fresh insights, strategies and global reach.
  • The board is considering how best to approach our cancelled meeting. In lieu of re-scheduling this year’s in-person meeting, we are planning to have virtual content covering some of the originally scheduled topics. Some discussion group topics will be carried over to the 2021 meeting, while others will be addressed virtually. We will communicate further on this soon.
  • Our newsletter will continue on a monthly basis.
  • Blog postings, which are aimed at either consumers or scientists, remain timely and popular – with new contributions posted on average every 2-3 weeks. Authored by board members and other experts in the field, these blogs provide a forum for opinions and observations on current issues and controversies as well as insights on global fermented foods, critical regulatory actions, and other relevant topics.
  • ISAPP filed comments on March 17 with the American Gastroenterological Association in response to their draft recommendations for probiotic use in GI conditions.
  • Spearheaded by former ISAPP IAC representative to the board, Dr. Roberta Grimaldi, ISAPP has subtitled several of the most popular ISAPP videos in different languages, including Dutch, French, Spanish, Russian, Japanese, Italian and Indonesian. The first of these should be posted by end of April.
  • The ISAPP-Students and Fellows Association has launched a blog program to provide perspectives by young scientists on issues of importance to the probiotic and prebiotic fields. They have also submitted a manuscript to Frontiers in Microbiology discussing a toolkit needed for their future in science: “Future of probiotics and prebiotics: an early career researchers’ perspective”.
  • Three consensus panels have been conducted since May of 2019. A manuscript arising from the synbiotics panel, chaired by Prof. Kelly Swanson, is in press with Nature Reviews Gastroenterology and Hepatology. The paper summarizing the consensus panel on fermented foods, chaired by Profs. Robert Hutkins and Maria Marco, is almost ready for submission to Nature Reviews Gastroenterology and Hepatology. A manuscript from the consensus panel on postbiotics, chaired by Prof. Seppo Salminen, is currently being written. All three papers are expected to provide clarity to the field with regard to definition of terms, current evidence for health benefits, and impact on stakeholders.
  • In addition to the three consensus panel papers in progress, several different ISAPP endeavors are at different stages of publication:
    • ISAPP vice president, Prof. Dan Merenstein, and executive science officer, Dr. Mary Ellen Sanders, worked with biostatistician and frequent ISAPP contributor, Prof. Dan Tancredi, to summarize evidence for clinical endpoints for probiotics, to be published in the Journal of Family Physicians. This paper, titled “Probiotics as a Tx resource in primary care”. The paper is currently in press.
    • Several ISAPP board members and other participants in a 2019 meeting discussion group recently submitted to Current Developments in Nutrition a paper titled “Dietary Recommendation on Adequate Intake of Live Microbes: A Path Forward”.
    • Marla Cunningham, the current IAC representative to the ISAPP board, has led an effort to compile results from the IAC Learning Forum from the 2019 ISAPP meeting on the topic of matrix effects impacting probiotic and prebiotic functionality. Manuscript in preparation.
    • Colin Hill and I represented ISAPP on a paper under review at Nutrients initiated by IPA-Europe titled “Criteria to qualify microorganisms as ‘probiotic’ in foods and dietary supplements”. This paper consolidates and fleshes out minimum criteria for use of the term ‘probiotic’ published by different groups, including the 2002 FAO/WHO working group, the 2014 ISAPP consensus paper on probiotics, and the 2018 ISAPP discussion group on global harmonization.
    • Glenn Gibson and Marla Cunningham are coordinating a paper titled “The future of probiotics and prebiotics in human health” as an output from their 2019 discussion group.

See here for all published ISAPP papers.

ISAPP board members, 2019 annual meeting

Messages about probiotics and COVID-19

With many conflicting and confusing health messages circulating during this global pandemic, including some criticisms of our field as well as some unsupported claims made by certain individuals and companies, ISAPP will remain an important touchstone for scientifically accurate information. Focusing on health effects is key to demonstrating probiotic and prebiotic efficacy, and we acknowledge that human studies are the ultimate measure of efficacy, but also, elucidating mechanisms of action help us understand how these interventions interface with the immune system and other mediators of health.  Currently, there is some evidence that certain probiotics/prebiotics can reduce the risk of viral infections (discussed in other blog posts here and here), but it is important to remember that they have not been studied specifically for COVID-19 prevention or treatment. This must be acknowledged when communicating with the wider community.

We greatly appreciate the continued support of our IAC members. The ISAPP Board, colleagues, and SFA will continue to chart a course forward in preparation for life after the pandemic. Our intent is to emerge from these experiences more connected and purposeful than ever. We welcome suggestions on how collectively we can endure and strengthen the science and communications that remain foundations of our field.

 

 

 

ISAPP Students and Fellows Association announce blog posting: A new way to share our work and perspectives

/in News, ISAPP Science Blog /by KC

By Anna-Ursula Happel, president ISAPP-SFA and postdoctoral fellow at the Faculty of Health Sciences at the University of Cape Town, South Africa

Our professors keep telling us to write, write, write. Reports, papers, reviews, presentations. You can’t blame them as that’s what most of them had to do, and in a competitive environment academic output is critical. But while professors urge students to produce academic outputs, there’s a whole world of research ‘impact’ in a digital world that is beginning to matter for career advancement. To further our reach along this axis, we as the ISAPP-Students and Fellows Association (SFA) are launching a blog platform, which will be regularly updated with perspectives from our members and ideas on recent developments in the field of probiotics and prebiotics.

Our very first blog post centered on an innovative project I never thought I would hear about. Through our SFA meeting, I had heard about the Reid lab from Western University in Canada trying to find a way to prevent the decline of honey bee populations. It was a shock, since their focus for years has been women’s health. My first question to one of Dr. Reid’s students, Brendan Daisley, was: How did this come about? It turns out, the interest in how environmental toxins affect humans led to wondering how it helped really important pollinators. Not such a tangential switch as I’d thought. But what’s this got to do with the field of probiotics and my career?

Well, it shows that probiotics, as the definition states, can be applied to many hosts. It also shows that the microbiome plays a role in the health of insects as well as humans. And many of the study tools are the same – microbiota analysis, bioinformatics, immune responses, etc., yet some are totally different – using Drosophila models, counting larvae, measuring honey volumes. Read more about it here. The lesson for me: think laterally, look at how you can apply your knowledge, think of ecosystem health, and learn lots of basic skills.

Then, I thought to myself, how can research provide me with opportunities for developing leadership, initiatives and skills that are valuable for my careers. How can I gain visibility as an early-career researcher, grow my networks, improve my writing and scientific communication skills and find a platform to highlight projects that matter to me? The new blog will be helpful for all of this.

As members of the SFA, we’re very fortunate to have our voices heard; to organize our own annual meeting (well, except for 2020 when the world shut down); to be exposed to amazing scientists and ground breaking ideas – and to communicate our work, ideas and perspectives to a broad audience through our new blog. Beyond formal networking at annual meetings, the SFA blog now offers a way to stay actively connected throughout the entire year on a more informal platform with our peers, may strengthen ties within the community and even lead to collaborations and career opportunities.

See here for the ISAPP-SFA blog — bookmark it or watch for new posts on social media!

Twitter: @ISAPPSFA

 

ISAPP discussion group leads to new review paper providing a global perspective on the science of fermented foods and beverages

/in Consumer Blog, ISAPP Science Blog, News /by KC

By Kristina Campbell, MSc, Science & Medical Writer

Despite the huge variety of fermented foods that have originated in countries all over the world, there are relatively few published studies describing the microbiological similarities and differences between these very diverse foods and beverages. But in recent years, thanks to the availability of high throughput sequencing and other molecular technologies combined with new computational tools, analyses of the microbes that transform fresh substrates into fermented foods are becoming more frequent.

A group of researchers from North America, Europe, and Asia gathered at the International Scientific Association for Probiotics and Prebiotics (ISAPP) 2018 conference in Singapore to discuss the science of fermented foods. Their goal was to provide a global perspective on fermented foods to account for the many  cultural, technological, and microbiological differences between east and west. This expert panel discussion culminated in a new review paper, published in Comprehensive Reviews in Food Science and Food Safety, entitled Fermented foods in a global age: East meets West.

Prof. Robert Hutkins, the paper’s lead author, says the diversity of panelists in the discussion group was an important aspect of this work. “Although we were all connected by our shared interests in fermented foods, each panelist brought a particular expertise along with different cultural backgrounds to our discussions,” he says. “Thus, one of the important outcomes, as noted in the published review paper, was how greatly historical and cultural factors, apart from microbiology, influence the types of fermented foods and beverages consumed around the world.”

The review captures the current state of knowledge on the variety of microbes that create fermented foods: whether these are starter cultures or microbes already present in the surrounding environment (i.e. the ‘authochthonous’ or ‘indigenous’ microbiota). The paper identifies general region-specific differences in the preparation of fermented foods, and the contrast between traditional and modern production of fermented foods—including the trade-offs between local and larger-scale manufacturing.

The authors of the article also took on the painstaking work of cataloging dozens of fermented foods from all over the world, including fermented milk products, fermented cereal foods, fermented vegetable products, fermented legume foods, fermented root crop foods, fermented meat foods, fermented fish products, and alcoholic beverages.

The expert panel discussions held every year at the ISAPP annual meeting provide a much-anticipated opportunity for globally leading scientists to come together to discuss issues relevant to scientific innovation and the direction of the field. This paper is an example of a concrete outcome of one of these discussion groups.

For more on fermented foods, see this ISAPP infographic or this educational video.

The small intestinal ‘mysteriome’: A potentially important but uncharted microbiome

/in Consumer Blog, ISAPP Science Blog /by KC

By Eamonn MM Quigley MD FRCP FACP MACG FRCPI, Lynda K and David M Underwood, Center for Digestive Disorders, Division of Gastroenterology and Hepatology, Houston Methodist Hospital, Houston, Texas, USA

 

Over recent years, countless publications have documented the status of the microbiota of the gastrointestinal tract by examining fecal samples. While this approach does provide a “snapshot” or representation of what is going on in the gut, and especially in the colon, it is a crude measure of the complex interactions between micro-organisms in the gut, as well as between these same microorganisms and us (their hosts). Fecal samples comprise a terminal microbial ecosystem, characterized by depletion of readily fermentable substrates, with a concomitant change in microbial composition, even compared to those farther upstream in the colon. It is unlikely, for example, that studies using fecal samples provide a full picture of what happens when bacteria (or other microorganisms) “talk” to the lining of the gut (the mucosa) or interact with the immune system of the intestine. Even less likely is that they provide any insights into bacterial populations in the small intestine, where most of the digestion of food and absorption of nutrients takes place. The small intestine also possesses the most abundant immune tissue of the entire gastrointestinal tract.

Yet, details of which bacteria actually inhabit this long and important organ, the small intestine, are sketchy. This lack of knowledge has apparently not restricted much theorizing and speculation about the role of an overgrowth of colonic-type bacteria (referred to as small intestinal bacterial overgrowth – SIBO) in the small intestine in many symptoms, disorders, and diseases. According to one especially popular theory – the “leaky gut” hypothesis – the list of conditions is nearly endless. The “leaky gut” hypothesizes that dysbiosis in the small intestine (in other words SIBO) and a disruption of the gut barrier leads to “leakage” of bacteria and bacterial products into the circulation causing inflammation, allergy, and autoimmunity.

There are several leaps of faith involved in “leaky gut” including, of course, the definition and diagnosis of SIBO. Traditional methods of diagnosing SIBO (obtaining fluid samples directly from the upper small intestine or a variety of breath tests) are fraught with problems and, in essence, have precluded a universally accepted definition of SIBO.

Fundamental to this dilemma is the definition of the normal small intestinal microbiome – how can we diagnose abnormal when we do not know the limits of normality? I would contend that, while there are situations where it is undoubted (based on the clinical context and various laboratory and other findings) that SIBO is an issue, there are countless more instances where SIBO is over-diagnosed and incorrectly implicated as the cause of an individual’s symptoms. This is an important issue as it can lead to the inappropriate use of antibiotics – something we all wish to avoid.

There is some good news – clever techniques exist for obtaining uncontaminated fluid samples from the small intestine, a capsule technology that permits live sampling of intestinal gases (generated by bacteria) as it traverses the intestine and the application, at last, of high-throughput sequencing, metagenomics, metabolomics, and metatranscriptomics to small intestinal microbiota suggest that the accurate definition of the normal small intestinal microbiome is not far off. At that time, we can all agree on an accurate and clinically meaningful definition of SIBO.

 

Is probiotic colonization essential?

/in Consumer Blog, ISAPP Science Blog /by KC

By Prof. Maria Marco, PhD, Department of Food Science & Technology, University of California, Davis

It is increasingly appreciated by consumers, physicians, and researchers alike that the human digestive tract is colonized by trillions of bacteria and many of those bacterial colonists have important roles in promoting human health. Because of this association between the gut microbiota and health, it seems appropriate to suggest that probiotics consumed in foods, beverages, or dietary supplements should also colonize the human digestive tract. But do probiotics really colonize? What is meant by the term “colonization” in the first place? If probiotics don’t colonize, does that mean that they are ineffective? In that case, should we be searching for new probiotic strains that have colonization potential?

My answer to the first question is no – probiotics generally do not colonize the digestive tract or other sites on the human body. Before leaping to conclusions on what this means for probiotic efficacy, “colonization” as defined here means the permanent, or at least long-term (weeks, months, or years) establishment at a specific body site. Colonization can also result in engraftment with consequential changes to the gut microbiota composition and function. For colonization to occur, the probiotic should multiply and form a stably replicating population. This outcome is distinct from a more transient, short-term (a few days to a week or so) persistence of a probiotic. For transient probiotics, it has been shown in numerous ways that they are metabolically active in the intestine and might even grow and divide. However, they are not expected to replicate to high numbers or displace members of the native gut microbiota.

Although some studies have shown that digestive tracts of infants can be colonized by probiotics (weeks to months), the intestinal persistence times of probiotic strains in children and adults is generally much shorter, lasting only few days. This difference is likely due to the resident gut microbiota that develops during infancy and tends to remain relatively stable throughout adulthood. Even with perturbations caused by antibiotics or foodborne illness, the gut microbiome tends to be resilient to the long-term establishment of exogenous bacterial strains. In instances where probiotic colonization or long-term persistence was found, colonization potential has been attributed more permissive gut microbiomes specific to certain individuals. In either case, for colonization to occur, any introduced probiotic has to overcome the significant ecological constraints inherent to existing, stable ecosystems.

Photo by http://benvandenbroecke.be/ Copyright, ISAPP 2019.

This leads to the next question: Can probiotics confer health benefits even if they do not colonize? My answer is definitely yes! Human studies on probiotics with positive outcomes have not relied on intestinal colonization by those microbes to cause an effect. Instead of colonizing, probiotics can alter the digestive tract in other ways such as by producing metabolites that modulate the activity of the gut microbiota or stimulate the intestinal epithelium directly. These effects could happen even on short-time scales, ranging from minutes to hours.

Should we be searching for new probiotic strains that have greater colonization potential? By extension of what we know about the resident human gut microbiota, it is increasingly attractive to identify bacteria that colonize the human digestive tract in the same way. In some situations, colonization might be preferred or even essential to impacting health, such as by engrafting a microbe that performs critical metabolic functions in the gut (e.g. break down complex carbohydrates). However, colonization also comes with risks of unintended consequences and the loss of ability to control the dose, frequency, and duration of exposure to that particular microbe.

Just as most pharmaceutical drugs have a transient impact on the human body, why should we expect more from probiotics? Many medications need to be taken life-long in order manage chronic conditions. Single or even repeated doses of any medication are similarly not expected to cure disease. Therefore, we should not assume a priori that any observed variations in probiotic efficacy are due to a lack of colonization. To the contrary, the consumption of probiotics could be sufficient for a ripple effect in the intestine, subtly altering the responses of the gut microbiome and intestinal epithelium in ways that are amplified throughout the body. Instead of aiming for engraftment directly or hand-wringing due to a lack of colonization, understanding the precise molecular interactions and cause/effect consequences of probiotic introduction will lead to a path that ultimately determines whether colonization is needed or just a distraction.

The threat of disease – Ignore science at your peril

/in featured, ISAPP Science Blog /by danielle

By Dr. Karen Scott, University of Aberdeen

We live in an age when life expectancy has increased and many diseases that used to be fatal are curable. Much of this is the result of years of efforts by dedicated scientists, painstakingly working out the causes of diseases, and then the best way to treat or prevent them. Yet the high profile of social media can boost the profile of results from poorly conducted studies, sometimes even beyond the publicity received by the original seminal results. Responsible scientists are partly to blame for this. We are a cagey bunch, frequently suffixing stories about our wonderful successes with caveats, maybes and the recurring refrain “more research is needed”. Those spreading sensationalist publicity have no such qualms.

Take vaccination for diseases caused by viruses. In 1796, Dr Edward Jenner realised that milk parlour girls did not seem to get small pox and theorised that they were protected from the devastating disease due to their continual exposure to the less dangerous cow pox virus. He proceeded to prove his theory by inoculating many people with cow pox, and then exposing them to the small pox virus. Although the experiment would nowadays perhaps be considered unethical, it worked and people infected with cow pox did not get small pox. This heralded the start of vaccination, a huge medical advance that has since protected millions of people from contracting polio, measles, mumps, rabies, tuberculosis and many more devastating diseases. In the 19th Century, Louis Pasteur advanced the method, using inactivated viruses as the inoculation. Vaccination has been so successful that small pox was ‘officially’ eradicated globally in 1979, and the polio vaccine, which was developed in 1955, has led to the virtual world-wide elimination of polio.

But more and more people people are declining to vaccinate their children. The very success of the vaccination scheme may be why it is now in danger. People have forgotten the devastating consequences and lasting effects of these diseases. In the western world it is now unusual to see people crippled by the effects of childhood polio. What about measles? Prior to vaccination, measles was a highly contagious disease, spreading through water droplets in air when an infected person sneezed. Forty percent of those with measles develop complications including pneumonia (which is often the case of measles-related deaths), deafness, blindness and encephalitis (brain swelling), which can even cause brain damage. If the patient survives, the effects of such complications can last for life. Yes – measles, a disease fully preventable by vaccination, kills. I was struck by a recent story about Roald Dahl, whose daughter sadly died after contracting measles when she was seven (see here). In 1986 Roald Dahl wrote an open letter describing his experience, encouraging people to vaccinate their children. The post was illustrated with a picture of a ward full of children suffering from polio, all confined in iron lungs as their breathing had been so badly affected due to paralysis of their chest muscles. No one can want to return to that.

Another contributor to reduced vaccination rates are reports that vaccinations cause more harm than good. Such reports are sustained in part by non-science-based social media claims. Even when original scientific reports are discredited, many parents continue to decide not to vaccinate their children.

How will these “anti-vaccination” parents/carers feel, sitting at the bedside of their critically ill child trying to make sense of the doctor’s explanation that even if their child pulls through, they will never be able to see again? Or explaining to their grown up child that he will never be able to father children due to an almost forgotten childhood disease? All because Mum and/or Dad paid more attention to a campaign on social media with no scientific basis, than to medical advice supported by decades of evidence? Yes, there are instances of people becoming ill with the diseases themselves, or suffering rare side effects of vaccination, but these are rare and pale in comparison to the morbidity and mortality prevented by vaccinations. After all, these same people do not stop driving their car to work when they hear that someone else had an accident doing so. The huge decline in epidemics of viral diseases following the introduction of vaccination programmes speaks to their effectiveness. The vaccine for measles was introduced in 1968 and is estimated to have prevented 20 million cases of measles and 4,500 deaths. In fact the vaccination programme was so successful that it led to the UK being declared ‘measles free’ in 2017.

 

 

 

 

 

 

 

Source – Public Health England; University of Oxford Vaccine Knowledge Project

Yet countries that we travel to on holiday still have measles outbreaks so it is still crucial to get children vaccinated. Even in the US and UK, the large increase in non-vaccinated children means that measles outbreaks (starting with people catching the disease abroad) are becoming more common – evidenced by the second graph above. An alarming statistic is that there are more cases of measles in 2018 than there were in 1998.

Increased numbers of unvaccinated people pose a threat to society at large. Herd immunity can protect a small number of unvaccinated individuals. Indeed, some individuals cannot be effectively vaccinated, including very young infants or when there is a problem with their immune system. But when the number of unvaccinated people rises, these viruses can ‘find’ susceptible hosts and take root once again in the population. This puts our most vulnerable society members at risk. The decision to not immunize is not a victimless decision. We need to maintain vaccination programmes on a global scale, to maintain ‘herd immunity’ and halt the current increase in the numbers of cases occurring.

Bottom line – vaccination works and prevents needless suffering from preventable diseases.

Another day, another negative headline about probiotics?

/in featured, ISAPP Science Blog /by ISAPP

By Prof. Colin Hill, PhD, APC Microbiome Ireland, University College Cork, Ireland

Scientists have a particular job. We try to discover what is unknown and we want to help to create a better understanding of the underlying forces, both physical and biological, that underpin our amazing universe. It is usually a slow and meticulous process. Gathering data usually takes weeks, or months, or years of work and so there is plenty of time to consider the numerous possible interpretations and the limitations and gaps in our understanding. Everything has to be repeated and subjected to statistical analysis. Finally, we publish our findings and our interpretation of that carefully accumulated data. Even this process takes weeks or months (or years) because of discussions with fellow authors and colleagues, numerous drafts of the manuscript, peer review and editorial comment. We are very aware that whatever we have published will almost certainly be repeated, or built upon, and if we are wrong (in either our data or our interpretation) that it will not withstand the test of time. Thus, we are slow and cautious and often qualify our findings with “this suggests” or “this strongly suggests” and we often finish with the unavoidable conclusion that “more research needs to be done”.

Journalists have a particular job. Journalists have to react quickly, perhaps in minutes or hours, to a breaking story or a commission from their editors, on topics with which they may not be familiar, and write short articles or present short pieces to camera that will appeal to the public and have a clear message. Nuance and complexity must often be left for long-form journalism or that as-yet unwritten novel. Being slow and complete and debating all of the possible interpretations is simply not an option. Finishing up with a cautious, equivocal “on the one hand, but also on the other hand” is also not really an option. Very few journalistic pieces end with “more journalism needs to be done”. It may also be difficult to construct a story along the lines of “some good science was well performed and led to careful and understated conclusions, which should really be repeated before we get too excited”.

It is not surprising then that scientists and journalists can sometimes find themselves at loggerheads. “Do probiotics work?” is a very reasonable question that a journalist can ask a scientist. “Well,” responds the scientist, “that depends on what you mean by ‘work’, and which probiotic you are asking about, and for what condition, and quite often strains are called probiotics but they do not fit the definition, and of course, there was that paper published last year which showed ……”. Cue frustration on both sides. Why can’t the scientist just answer the question? And why can’t the journalist understand that just because a question can be simply stated does not mean that it has a simple answer? Ask a doctor “do pills work?” and you might very well get a similarly convoluted answer, but no one would think it evasive. No wonder the scientist sometimes ends up reading the resultant article in frustration – how did the journalist come to that conclusion, where did all my careful explanations go? Of course, most scientists are imagining his or her scientific colleagues reading the article and wondering at the ‘incomplete’ or ‘trivial’ response. While the journalist may well wonder what planet the scientist lives on if he or she thinks that the editor is going to publish a long essay capturing all of the subtlety of the research.

This almost certainly comes across as me implying that scientists are impeccable purveyors of truth and that journalists are willing to sacrifice truth for simplicity, but I truly am not suggesting that. In almost every instance there is no bad faith involved from either party, it is simply the consequence of the different demands placed on two very different and very valuable roles in society.

So, these things will happen. We will see newspaper articles and online pieces (or editorial comments in journals) that do not contain all the nuance and complexity of the complex paper which it is based. We will see press articles that draw simple and reader-friendly conclusions. “Probiotics quite useless”, “Are probiotics money down the toilet? Or worse?”, etc. So, how should we respond? Do we write erudite articles pointing out the limitations of the commentator, coming across perhaps as arrogant or supercilious? [And yes, of course I use the words erudite and supercilious because it makes me feel better than you.] Do we send angry missives complaining about the article, and perhaps risk drawing further attention to it?

If you are asked by a journalist to comment on a paper, or if your local/national paper or favourite website has published an article that you think is unfair, perhaps the way to respond is to have a few simple questions of your own which can be put to journalists and/or readers. Perhaps we can use a checklist such as the following:

  • Is the article describing an original piece of research and was it published in a reputable, peer-reviewed journal?
  • What evidence is there that the strain or strain mix in question is actually a probiotic? Does it fit the very clear probiotic definition?
  • Was the study a registered human trial? How many subjects were involved? Was it blinded and conducted to a high standard?
  • What evidence was presented of the dose administered and was the strain still viable at the time of administration.
  • Were the end points of the study clear and measurable? Are they biologically or clinically significant to the subjects?
  • Did the authors actually use the words contained in the headline? “Useless”, or “waste of money”, etc?

Once these relatively simple questions are answered, then we can move on to the details and the complexities, but that is not where we should start. Of course, if a study is well performed and reaches a negative conclusion we should absolutely acknowledge that. But we can still point out that one strain or strain mix not working under one set of conditions is only evidence of the fact that one particular strain or strain mix does not work under one particular set of conditions. It does not warrant a blanket condemnation or criticism of all probiotics. Maybe ask the journalist to think about the obvious flaws in the headline ‘Headache pill does not cure cancer, all pills obviously a waste of money!”, and ask why the same standards should not be applied to probiotics?

Scientists and journalists have different roles in society, that is clear, but we can assume a priori that both have clear motives and do not want to mislead readers. Let’s start from there and make it easier for both sides to work together to make the public aware of the very real potential, and very real limitations, of probiotics and prebiotics in preserving health in a society in dire need of practical solutions.

The Art of Interpretation

/in featured, News /by ISAPP

By Prof. Gregor Reid, BSc Hons PhD MBA ARM CCM Dr HS, Lawson Research Institute, University of Western Ontario, Canada

It takes a certain degree of intelligence to become a scientist, and certainly hard work to be able to fund a lab and students. Yet, is it not bemusing when scientists cannot interpret simple things like definitions and the results of human studies?

I’ve written repeatedly, as have others, about the definition of probiotics (in case you forgot – “Live microorganisms that, (or which) when administered in adequate amounts, confer a health benefit on the host”),1,2 and yet people look at it and must think that ‘dead’ fits, as does ‘consume’, as does ‘colonize’. It beggar’s belief how such a simple definition can be so badly interpreted by intelligent people.

Time after time papers I review mis-write and/or misinterpret the definition. Conference after conference, I hear dieticians, pharmacists, physicians, scientists not only get the definition wrong, but say things like ‘the probiotics in kombucha’ when there are none, ‘we have lots of probiotics in our gut’ when you don’t unless you consumed them, ‘the lactobacilli need to colonize’ when this was never a prerequisite nor does it happen except in rare instances.

The interpretation gets more difficult when people use terms that are completely undefined like ‘psycho-biotics’ and ‘post-biotics’. Even ‘dead probiotics’ have been used in clinical trials – God help us when the authors can’t even define it. Why stop at killing probiotic strains? Why not just kill any bacterial strain? Even the gut-brain axis which is now mentioned everywhere in the literature is undefined and unproven. The vagus nerve links to many body sites as does the nervous system, making it exceedingly difficult to prove that brain responses are only due to the gut microbes.

Everyone can site a manuscript that has been badly analyzed, interpreted or peer-reviewed, or whose findings are overblown. But let’s not excuse this as ‘it’s just science’ or ‘it’s just the way it is.’ No, it is not. When a paper uses a product that is stated to be ‘probiotic’, there is an onus on the authors to make sure the product meets the appropriate criteria. These have been stated over and over again and reiterated this March, 2019.3

If scientists and science writers are really that smart, then how do they keep getting this wrong? How do we let a poorly analyzed paper get published and allow authors to say that Bacteroides fragilis is a probiotic that can treat autism?4,5 And when this leads to companies claiming probiotics can treat autism, why do other scientists convey cynicism for the field instead of against their colleagues and specific companies making the false claims?

Where does opinion cross the line with ignorance or stupidity? Martin Luther King Jr. must have predicted life today when he said, “Nothing in all the world is more dangerous than sincere ignorance and conscientious stupidity.”

Is it envy or anger that drives the anti-probiotic sentiments? It seems to go far beyond a difference of opinion. When the BBC and JAMA fail to comment on two much better and larger studies on the effects of probiotics published6,7 at the same time as the ones in Cell8,9 that were promoted by press releases, what is driving opinion? The science or the press releases? Are the journalists and communications’ people interpreting study results vigorously? One cannot believe they are.

In an era where anyone can write anything at any time and pass it along to the world, what are we recipients to do? Just go with our instincts? Soon, we will not know the difference between fact and fake news. The avatars will be so real, we will act on falsehoods without knowing. When all news is fake, where does that leave us as people, never mind scientists?

Manuscripts are sent for peer-review but how many reviewers are experts in bioinformatics, molecular genetics, clinical medicine, biostatistics and what happens on the front line of products to consumers or patients? Like it or not, poor studies will get out there and it will be the media who will tell the story and interpret the findings or press releases.

One must hope that confirmatory science will continue and if it fails, the writers and readers will stop citing the original incorrect report. But how often does that happen? And what are we left with?

It takes effort to object or fight back, but if we don’t then the fake news will become the norm.

Try interpreting that if you will.

 

Literature Cited

  1.  FAO/WHO. 2001. Probiotics in food.  http://www.fao.org/food/food-safety-quality/a-z-index/probiotics/en/
  2. Hill C. et al. 2014. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotics. Nat. Reviews Gastroenterol. Hepatol. 11(8):506-14.
  3. Reid G. et al. 2019. Probiotics: reiterating what they are and what they are not. Front. Microbiol. 10: article 424.
  4. Hsiao et al. 2013. Microbiota modulate behavioral and physiological abnormalities associated with neurodevelopmental disorders. Cell. 155(7):1451-63.
  5. Sharon G, et al. 2016. The central nervous system and the gut microbiome. Cell. 167(4):915-932.
  6. Korpela K. et al. 2018. Probiotic supplementation restores normal microbiota composition and function in antibiotic-treated and in caesarean-born infants. Microbiome. 6(1):182.
  7. De Wolfe, T.J. et al. 2018. Oral probiotic combination of Lactobacillus and Bifidobacterium alters the gastrointestinal microbiota during antibiotic treatment for Clostridium difficile infection. PLoS One. 13(9):e0204253.
  8. Suez J. et al. (2018). Post-antibiotic gut mucosal microbiome reconstitution is impaired by probiotics and improved by autologous FMT. Cell. 2018 Sep 6;174(6):1406-1423.e16.
  9. Zmora N. et al. 2018. Personalized gut mucosal colonization resistance to empiric probiotics is associated with unique host and microbiome features. Cell. Sep 6;174(6):1388-1405.e21.