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Episode 9: An evolutionary perspective on fermented foods

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.

An evolutionary perspective on fermented foods, with Assoc. Prof. Katie Amato

Episode summary:

In this episode, the ISAPP hosts talk about fermented foods and non-human primates with Katie Amato of Northwestern University, USA. Amato describes what she has learned from studying the gut microbiota of non-human primates and how it relates to our understanding of human and gut microbial co-evolution over time. She also talks about non-human primate behaviors around fermented foods and what they might tell us about the need for human fermented food consumption.

Key topics from this episode:

  • A list of species categorized as non-human primates.
  • Changes in the gut microbiota of primates depend on habitats and available food across different seasons.
  • Primates in captivity have a different gut microbiota from wild ones – for example, animals kept in the zoo have a lower gut microbiota diversity.
  • Fermentation as a process to improve access to nutritional components of food; knowledge about primates’ use of fermentation and their gut microbes can tell us something about early human evolution.
  • Primates may derive benefits from using fermented foods. Consumption of fermented foods (overripe fruits) by primates is linked to certain habitats and climate factors; some non-human primates appear to intentionally leave fruits to ferment before returning to consume them.
  • There are benefits to translating the knowledge obtained from studying gut microbiota of primates to humans. 

 

Episode abbreviations and links:

Dissertation study: The Gut Microbiota Appears to Compensate for Seasonal Diet Variation in the Wild Black Howler Monkey (Alouatta pigra)

Study: Fermented food consumption in wild nonhuman primates and its ecological drivers

Mentors mentioned: Kathy Cottingham, Matt Ayres, David Peart, John Gilbert, Mark McPeek, Craig Layne, Rob McClung.
Steve Ross, Alejandro Estrada, Paul Garber, Angela Kent, Rod Mackie, Steve Leigh, Rob Knight.

Additional resources:

Research on the microbiome and health benefits of fermented foods – a 40 year perspective. ISAPP blog
New ISAPP-led paper calls for investigation of evidence for links between live dietary microbes and health. ISAPP blog

 

About Assoc. Prof. Katie Amato:

Dr. Amato is a biological anthropologist at Northwestern University studying the influence of gut microbes on host ecology and evolution. Her research examines how changes in the gut microbiota impact host nutrition, energetics, and health. She uses non-human primates as models for studying host-gut microbe interactions in selective environments and for providing comparative insight into the evolution of the human gut microbiota. Her main foci are understanding how the gut microbiome may buffer hosts during periods of nutritional stress and how the gut microbiome programs normal inter-specific differences in host metabolism. Dr. Amato is the President of the Midwest Primate Interest Group, an Associate Editor at Microbiome, an Editorial Board member at Folia Primatologica, and a Fellow for the Canadian Institute of Advanced Research’s ‘Humans and the Microbiome’ Program.

Can diet shape the effects of probiotics or prebiotics?

By Prof. Maria Marco PhD, University of California – Davis and Prof. Kevin Whelan PhD, King’s College London

If you take any probiotic or prebiotic product off the shelf and give it to several different people to consume, you might find that each person experiences a different effect. One person may notice a dramatic reduction in gastrointestinal symptoms, for example, while another person may experience no benefit. On one level this is not surprising, since every person is unique. But as scientists, we are interested in finding out exactly what makes a person respond to a given probiotic or prebiotic to help healthcare providers know which products to recommend to which people.

Among factors that might impact someone’s response to a probiotic or prebiotic – such as baseline microbiota, medications, and host genetics – diet emerges as a top candidate. Ample evidence has emerged over the past ten years that diet has direct and important effects on the structure and function of the gut microbiome. Overall the human gut microbiome is shaped by habitual diet (that is, the types of foods consumed habitually over time), but the microbes can also can fluctuate in response to short-term dietary shifts. Different dietary patterns are associated with distinct gut microbiome capabilities. Since probiotics and prebiotics may then interact with gut microbes when consumed, it is plausible that probiotic activity and prebiotic-mediated gut microbiome modulation may be impacted by host diet.

A discussion group convened at ISAPP’s 2022 annual meeting brought together experts from academia and industry to address whether there is evidence to support the impact of diet on the health effects of probiotics and prebiotics. To answer this question, we looked at how many probiotic or prebiotic studies included data on subjects’ diets.

  • Prebiotics: Our review of the literature showed that only a handful of prebiotic intervention studies actively measured background diet as a potential confounder of the effect of the prebiotic. One such study (Healey, et al., 2018) classified individuals based on habitual fiber intake, and in doing so found that the gut microbiome of individuals consuming high fiber diets exhibited more changes to microbiome composition than individuals with low fiber intake. While both groups consuming prebiotics showed enrichment of Bifidobacterium, those with high fiber intake uniquely were enriched in numerous other taxa, including butyrate-producing groups of microbes. Prebiotics also resulted in improved feelings of satiety, but only among the high fiber diet consumers.
  • Probiotics: We found no evidence of published human RCTs on probiotics that investigated diet as a possible confounding factor. This is a significant gap, since we know from other studies that host diet affects the metabolic and functional activity of probiotic lactobacilli in the digestive tract. Moreover, the food matrix for the probiotic may further shape its effects, via the way in which the probiotic is released in situ.

Our expert group agreed that diet should be included in the development of new human studies on probiotics and prebiotics, as well as other ‘-biotics’ and fermented foods. These data are urgently needed because although diet may be a main factor affecting outcomes of clinical trials for such products, it is currently a “hidden” factor.

We acknowledge there will be challenges in taking diet into account in future trials. For one, should researchers merely record subjects’ habitual dietary intake, or should they provide a prescribed diet for the duration of the trial? The dietary intervention (nutrient, food, or whole diet) must also be clearly defined, and researchers should carefully consider how to measure diet (e.g. using prospective or retrospective methods). In the nutrition field, it is well known that there are challenges and limitations in the ways dietary intake is recorded as well as the selection of dietary exclusion criteria. Hence, it is crucial that dietitians knowledgeable in dietary assessment and microbiome research contribute to the design of such trials.

If more probiotic and prebiotic trials begin to include measures of diet, perhaps we will get closer to understanding the precise factors that shape someone’s response to these products, ultimately allowing people to have more confidence that the product they consume will give them the benefits they expect.

Episode 8: The link between digestive symptoms, IBS and the gut microbiota: A gastroenterologist’s perspective

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 link between digestive symptoms, IBS and the gut microbiota: A gastroenterologist’s perspective, with Prof. Eamonn Quigley

Episode summary:

In this episode, the ISAPP hosts focus their discussion around irritable bowel syndrome (IBS) with Prof. Eamonn Quigley, MD, of Weill Cornell Medical College. Prof. Quigley says patients are increasingly curious about the link between IBS and gut microbiota. He outlines what we know so far about the etiology of IBS, and the evidence for how gut microbiota may contribute to the condition as well as possible interventions that target the gut microbes.

Key topics from this episode:

  • What are the symptoms of IBS?
    The typical symptoms is abdominal pain associated with a disturbance in bowel function which could be diarrhea or constipation, or even alternating between them, depending on the patient.
  • How prevalent is IBS?
    Estimates say 5-10% of all people globally have IBS.
  • What is the etiology of IBS?
    There is no clear cause for IBS identified to date. IBS has been linked to the gut-brain axis (as it often co-occurs with depression and anxiety), gut microbiota, diet, previous gastrointestinal infections (Salmonella, Shigella, Campylobacter infections), and antibiotic use. It is also more common in women.
  • How is IBS treated?
    Approaches have tended to focus on treatment of symptoms: for example, treating the pain or diarrhea. Diet has also become an essential part of IBS treatment. But overall quality of life for IBS patients is of crucial importance. The focus should not be only on treating symptoms but also on improving their quality of life.
  • Are probiotics effective for IBS? A short history and perspective on how to develop probiotics for IBS.
  • Effects of the COVID-19 pandemic and COVID-19 infections in IBS patients – lessons learned from other viral infections. 
  • Is the gut microbiota the “Holy Grail” for gastrointestinal health? We still have a lot to learn, especially regarding clinical applications.

 

Episode abbreviations and links:

FODMAP: fermentable oligosaccharides, disaccharides, monosaccharides and polyols (i.e. types of carbohydrates that are poorly absorbed in the small intestine).

EMA: European Medicines Agency (i.e. the European counterpart of the US Food and Drug Administration)

Study: Lactobacillus and bifidobacterium in irritable bowel syndrome: Symptom responses and relationship to cytokine profiles

CME course on digestion and gut microbiota: Android version, iOS version, web version

 

Additional resources:

I have IBS – should I have my microbiome tested? ISAPP blog
The Microbiome — Can it aid in the diagnosis and therapy of irritable bowel syndrome (IBS)? ISAPP blog

 

About Prof. Eamonn Quigley:

Eamonn M M Quigley MD FRCP FACP MACG FRCPI MWGO is David M Underwood Chair of Medicine in Digestive Disorders and Chief of the Division of Gastroenterology and Hepatology at Houston Methodist Hospital. A native of Cork, Ireland, he graduated in medicine from University College Cork. He trained in internal medicine in Glasgow, completed a two-year research fellowship at the Mayo Clinic and training in gastroenterology in Manchester, UK. He joined the University of Nebraska Medical Center in 1986 where he rose to become Chief of Gastroenterology and Hepatology. Returning to Cork in 1998 he served as Dean of the Medical School and a PI at the Alimentary Pharmabiotic Center. He served as president of the American College of Gastroenterology and the WGO and as editor-in-chief of the American Journal of Gastroenterology.

Interests include IBS, gastrointestinal motility and the role of gut microbiota in health and disease. He has authored over 1000 publications and has received awards and honorary titles world-wide. Married for over 40 years to Dr Una O’Sullivan they have 4 children and three grandchildren. Interests outside of medicine include literature, music and sport and rugby, in particular; Dr Quigley remains a passionate supporter of Munster and Irish rugby.

Do polyphenols qualify as prebiotics? The latest scientific perspectives

Kristina Campbell, Consulting Communications Director, ISAPP

When the ISAPP scientific consensus definition of ‘prebiotic’ was published in 2017, the co-authors on the paper included polyphenols as potential prebiotic substances. At the time, the available data on the effect of polyphenols on the gut microbiota were insufficient to show a true prebiotic effect.

An ISAPP webinar held in April 2022, aimed to give an update on the health effects of polyphenols and their mechanisms of action, along with how well polyphenols fit the prebiotic definition. Prof. Daniele Del Rio from University of Parma, Italy, and Prof. Yves Desjardins from Université Laval, Canada, presented the latest perspectives in the field.

What are polyphenols?

Polyphenols are a group of compounds found in plants, with over 6000 types identified to date. They can be divided into two main categories, flavonoids and non-flavonoids.

Polyphenols are absorbed in two different ways in the body. A very small fraction is absorbed in the small intestine, but 95% of them reach the lower gut and interact with gut microbiota. Although polyphenols have a special capacity to influence the activities of microorganisms, some resident microorganisms, in turn, can change the chemical structure of polyphenols through enzymatic action. These interactions produce a unique array of metabolites, which may be responsible for some of polyphenols’ prebiotic effects.

What are the health effects of polyphenols?

Epidemiological studies show that polyphenols in the diet are associated with many health benefits, including prevention of cardiovascular disease, certain cancers, and metabolic disease. These effects occur through various mechanisms. However, association is not proof of causation. So how good is the evidence that polyphenols can lead to health benefits?

Numerous human studies exist, but the most robust study to date for the health benefits of polyphenols is a randomized, controlled trial of over 20,000 adults, published in 2022, which showed supplementation with cocoa extract reduced death from cardiovascular events (although it did not reduce the number of cardiovascular events).

What are the mechanisms of action for polyphenols?

Polyphenols have multiple mechanisms of action. Del Rio focuses on the metabolites produced from dietary polyphenols called flavan-3-ols, which are found in red wine, grapes, tea, berries, chocolate and other foods. Along with colleagues, he showed that the metabolites produced in response to a polyphenol-rich food occur two ‘waves’: a small wave in the first 2 hours after ingestion, and a larger wave 5-35 hours after ingestion. The second wave is produced when flavan-3-ols reach the colon and interact with gut microbiota.

Work is ongoing to link these metabolites to specific health effects. Along these lines, Del Rio described a study showing how cranberry flavan-3-ol metabolites help defend against infectious Escherichia coli in a model system of bladder epithelial cells. These polyphenols are transformed by the gut microbiota into smaller compounds that are absorbed—so the health benefit comes not from the activity of polyphenols directly, but from the molecule(s) that the gut microbiota has produced from the polyphenols.

How else do polyphenols work? Ample evidence suggests polyphenols interact in different ways with gut microbes: they have direct antimicrobial effects, they affect quorum sensing, they compete with bacteria for some minerals, and/or they modify ecology, thereby affecting biofilm formation. Desjardins explained that these interactions may occur in parallel: for example, polyphenols may exert antimicrobial effects when they reach the colon, and at the same time, microorganisms in the gut begin to degrade them.

The mode of action of polyphenols Desjardins studies is the prebiotic mode of action—or as he describes it, “prebiotic with a twist”. A landmark paper from 2015 showed how cranberry polyphenols had protective effects on metabolism and obesity through the creation of mucin in the intestine, which formed a good niche for Akkermansia muciniphila, a keystone bacterial species for good metabolic health. Other polyphenols have since been shown to work the same way: by stimulating production of mucin, thereby providing ideal conditions for beneficial bacteria to grow. In this way, polyphenols appear to show small-scale effects comparable to the effects of probiotics, by inducing a host response that alters the bacterial niche.

Are the effects of polyphenols individual?

Del Rio offered some evidence that the health effects of polyphenols, via metabolites, is personalized: a study showed the existence of three distinct patterns of metabolite production in response to dietary polyphenols (ellagitannins). These may depend on the particular microbes of the gut and their ability to produce the relevant metabolites—so in essence, in each case the gut microbiota is equipped to produce a certain set of metabolites in response to polyphenols. More work is needed, however, to be able to personalize polyphenol intake.

Do polyphenols qualify as prebiotic substances?

Polyphenols clearly interact with gut microbiota to influence human health. The definition of a prebiotic is “a substrate that is selectively utilized by host microorganisms conferring a health benefit”. Given the available evidence that polyphenols are not metabolized or utilized by bacteria in all cases in the same direct way as carbohydrate prebiotics, Desjardins sees them as having a “prebiotic-like effect”. Rather, polyphenols are transformed into other biologically active molecules that ultimately provide health benefits to the host. These prebiotic-like properties of polyphenols are nicely summarized in a 2021 review paper and include decreasing inflammation, increasing bacteriocins and defensins, increasing gut barrier function (thereby reducing low-grade inflammation), modulating bile acids, and increasing gut immuno-globulins.

Overall, the speakers showed that polyphenols exert their health effects in several ways—and while the gut microbiota are important for their health effects, polyphenols, as a heterogenous group, may not strictly meet the criteria for prebiotics. Clearly, more research on polyphenols may reveal other mechanisms by which these important nutrients influence the gut microbiome and contribute to host health, and they may someday be regarded as prebiotics.

Watch the replay of the ISAPP webinar here.

Domestic horses from different geographical locations harbor antibiotic resistant gut bacteria, unlike their wild counterparts

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

It all started on the 12-hour ferry trip that links Turku with Stockholm during one of the last still warm- summer days of September 2016, when a group of scientists met: Seppo Salminen, Miguel Gueimonde, Carlos Gómez- Galllego and Akihito Endo (joining us virtually from Japan well before the pandemic made these virtual meetings so popular). One of the topics was the possibility of conducting a study comparing the gut microbiome of feral and domestic horses. We had no specific funding for the project but we agreed it would be worthwhile and all agreed to participate.

Misaki wild horses from Cape Toi’s Reserve, Japan. Photo courtesy of Seppo Salminen.

Domesticated horses live under different conditions compared with their wild ancestors. We hypothesized that the animals’ housing, regular veterinary care and feeds would lead to an altered microbiota compared to wild horses. The project was ambitious and challenging in several ways: we aimed at sequencing all microbes, not just bacteria, by using whole genome sequencing; sampling droppings from feral horses needed special permission from the parks or reserves where these horses were held; the project required shipping samples from different parts of the world to the same place where they would be processed; and this all had to be managed without specific financial support to cover the expenses. Curiosity, personal dedication and funding from each end fueled this project.

Little by little, samples of feces of feral and domestic horses were collected in Argentina, Finland, Spain, Russia and Japan. Fecal DNA was extracted in every sampling location and sent to Prof. Li Ang in China for whole genome sequencing and data analysis.  A remarkable contribution was made by Prof. Ang and his team from the Zhengzhou University in China. In his words:

The biggest challenge was that very few sequences (less than 5%) were from known species hosted in the gut of horses. This number is usually 50-60% or 80-90% in human adults or infants gut microbiota, respectively. Thus we had to use ‘old school methods’ to get microbiota profiles, by constructing a custom reference database with whole genomes and then choosing specific alignments, a process that required thousands of computing hours. Interestingly, we found some specific species in horses from different locations. For example, we found shiitake mushroom in Japanese horses, a common food in East Asia families, but not in horses from other locations.

Cimarron wild horses from the State Park Ernesto Tornquist, Argentina. Photo courtesy of Seppo Salminen.

The fecal microbiome of 57 domestic and feral horses from five different locations on three continents were analyzed, observing geographical differences. A higher abundance of eukaryota (p < 0.05) and viruses (p < 0.05) and lower abundance of archaea (p < 0.05) were found in feral animals when compared with domestic ones. The abundance of genes coding for microbe-produced enzymes involved in the metabolism of carbohydrates was significantly higher (p < 0.05) in feral animals regardless of the geographic origin, which may reflect the fact that feral horses are exposed to a much more diverse natural vegetal diet than their domesticated counterparts. Differences in the fecal resistomes between both groups of animals were also observed. The domestic/captive horse microbiomes were enriched in genes conferring resistance to tetracycline, likely reflecting the use of this antibiotic in the management of these animals. Our data also showed an impoverishment of the fecal microbiome in domestic horses with diet, antibiotic exposure and hygiene being likely drivers, a fact that has been also reported for us, humans.

Almost 6 years passed since the results of those ideas discussed on board a ferry slowly galloped into the cover of the February edition of Nature Communications Biology. We hope this will be a starting point for more work that can help uncover the best ways to support equine health.

Hands holding mobile phone

Virtual events continue to fill gaps as in-person meetings are being planned

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

For scientists, annual meetings provide coveted opportunities to hear about the latest scientific advances from expert researchers, and they are where students and trainees get to present their research, often for the first time. Of course, meeting and socializing with colleagues, both new and old, during breaks and evening sessions is also an important part of these conferences.

Yet over the past two years, most occasions to meet face-to-face were canceled. Virtual meetings became the new normal and, even though a poor substitute for in-person gatherings, provided opportunities to connect and share emerging science. As we anticipate being together again in person – hopefully for 2022 meetings – take note of three upcoming conferences to fill the gap. Each of these feature meetings are related to the gut microbiome, diet, and health.

(1) In October, the Agriculture and Health Summit: Cultivating Gut Health at the Crossroads of Food & Medicine is a FREE three-day virtual conference that brings together a unique combination of researchers, industry leaders and thought leaders from the biomedical and agricultural sectors for important conversations about the future of human health. The event will provide a rare opportunity for individuals with diverse areas of expertise to discuss opportunities and challenges in creating ‘foods for health’ through the gut microbiome, working toward solutions in nutrition and medicine. More information can be found here. Among the presenters are ISAPP Executive Science Officer, Mary Ellen Sanders, and board members, Dan Merenstein and Bob Hutkins.

 

(2) Then in November, a Nature-sponsored online conference called Reshaping the Microbiome through Nutrition will be held. According to the website, “this conference will bring together researchers working on the microbiome and nutrition to discuss how our microbiota use and transform dietary components, and how these nutrients and their products influence host health throughout life, including effects on development and infectious and chronic diseases. A central theme of the meeting will be how diet and dietary supplements could be harnessed to manipulate the microbiome with the aim of maintaining health and treating disease”More information is found here.

(3) Another meeting in November is organized across ten centers/institutes at the NIH and the Office of Dietary Supplements and the Office of Nutrition Research. This two-day conference November 5 and 8, titled Precision Probiotic Therapies—Challenges and Opportunities, features a Keynote address by Prof. Jeff Gordon, from the Washington University School of Medicine. ISAPP president Prof. Dan Merenstein, Georgetown University School of Medicine, is also presenting. To register for this FREE meeting, see here.

 

In this current era, interest in how diet (including probiotics, prebiotics, and fermented foods) influences the microbiome and affects human and animal health has never been greater, as is evident by these and other similarly-themed conferences.

ISAPP is planning its next annual by-invitation meeting, to be held in person.

 

Do antibiotics ‘wipe out’ your gut bacteria?

By Dr. Karen Scott, University of Aberdeen, UK

Antibiotics have been an important tool in medicine to kill pathogenic bacteria and treat infectious diseases for many decades. But for most of those decades, scientists had limited awareness of the community of ‘good’ microbes that reside in our guts and other parts of the body. Now that we have ample evidence of the beneficial functions of these abundant resident microbial communities, we need to be aware of the potential impact antibiotics may have on them – and whether antibiotics might wipe them out, creating a different health problem.

Antibiotics act against basic cellular functions of microbes – targeting cell wall synthesis, DNA/RNA synthesis, protein synthesis and folate synthesis. In order to avoid the effects of the antibiotics, bacteria can either alter their own target molecule so that the antibiotic is ineffective, actively pump the antibiotic out of the cell, or inactivate the antibiotic. With bacteria constantly trying to survive in the face of antibiotics, we are in a continuous race to ensure that the disease-causing bacteria we are trying to eliminate remain susceptible to the antibiotics used to treat them.

The action of antibiotics against bacteria can be classified according to:

  • Bacteriostatic (inhibiting growth of the target microorganism) vs. bactericidal (killing cells)
  • Narrow spectrum (acting against a few specific bacteria) vs. broad spectrum (acting indiscriminately against many bacteria).

Clearly an ‘ideal’ antibiotic would be narrow spectrum and bactericidal, rapidly killing only the target bacteria. In contrast a broad spectrum, bacteriostatic antibiotic may only inhibit growth of the target bacterium and at the same time may be bactericidal to others.

And here we come to the basic problem of antibiotic use in general medicine. When a patient attends the doctor’s office with a complaint such as a sore throat or an ear infection, most likely due to a viral infection, the doctor has a few choices:

  1. The doctor can inform the patient that antibiotics would be ineffective, and that the infection will go away by itself in a few days, and that the patient go home, rest and take other remedies to target symptoms such as pain, fever, or congestion in the meantime.
  2. The doctor can succumb to pressure from the patient demanding a prescription ‘remedy’ and prescribe an unnecessary and useless course of antibiotics. While this was common in the past, in many countries doctors now stand firm, maintaining antibiotics would be ineffective and are not required.
  3. The doctor can offer a delayed antibiotic prescription – sending the patient away with a prescription but advising the patient to wait for a couple of days to see if symptoms resolve before deciding if the prescription is required. This approach is becoming more common and does reduce unnecessary antibiotic use.
  4. Finally, the doctor can determine that even if the original illness was caused by a virus, there is now a secondary bacterial infection and that a course of antibiotics is now required. The problem here is that without a laboratory test the doctor cannot be sure which bacterium is causing the disease so in order to be sure that the antibiotic will be effective, a broad spectrum antibiotic is often prescribed.

Any antibiotic prescription that the patient collects from the chemist (pharmacist) and starts taking, immediately causes collateral damage to their own resident microbiota. It is now well-established that a short course of antibiotics disrupts the gut bacterial community, killing many important resident bacteria. This can be observed by a reduction in diversity (see articles here and here, and figure here), meaning that fewer different bacterial groups can be detected. Normally once the patient stops taking the antibiotic the diversity of the community increases within a month, almost returning to the starting composition. Almost. Some bacterial species are particularly sensitive to certain antibiotics and may never recover. Oxalobacter formigenes, the bacterium that protects against kidney stone formation, is one example.

The other hidden effect of antibiotic treatment is that although all members of the microbial community may re-establish, they may not be the same as before. The levels of antibiotic resistance amongst bacteria isolated from samples from patients after seven days of antibiotic treatment were much higher than those from controls without any treatment, even four years later (see here). The selection pressure exerted on bacteria during short courses of antibiotic treatment results in transfer of antibiotic resistance genes, and the spread of resistance to many other members of the microbial community, increasing the overall resistance profile. Whilst this may not be immediately damaging to the health of the person, this change in baseline resistance does mean that a subsequent course of antibiotic treatment could be less successful because more bacteria will be able to withstand being affected by the antibiotic, and more bacteria will contain resistance genes that could be transferred to disease-causing bacterium.

Historically, as soon as we started using purified antimicrobials therapeutically, we started seeing rise of resistance to those antibiotics. The first recognised tetracycline resistance gene, otrA, was identified in Streptomyces, a genus of Gram-positive bacteria now known to produce many antimicrobial agents as secondary metabolites (see figure here).

The indiscriminate effects of antibiotics can be even more severe in hospitalised patients. Recurring Clostridioides difficile-associated diarrhoea (CDAD) is a direct consequence of antibiotic treatment. The microbial diversity decreases in patients receiving antibiotics for legitimate therapeutic reasons, and the Clostridioides difficile population expands to occupy empty niches. Overgrowth of C. difficile results in toxin production, abdominal pain, fever and ultimately CDAD. Treatment is difficult because some C. difficile strains are antibiotic resistant and C. difficile forms non-growing spores that persist during the antibiotic treatment. This means that even if the initial infection is successfully treated, once the antibiotic treatment ceases the spores can germinate and cause recurring C. difficile infections. Although initial treatment with antibiotics works for 75% of patients, the remaining 25% end up with recurring CDAD infections. A more effective treatment may be faecal microbial transplant (FMT) therapy (see blog post here).

Scientists have spent the last 20 years investigating the many ‘good microbes’ that inhabit our intestinal tracts leading to a much greater understanding of what they do, and the potential repercussions when we destroy them. This means we are now very aware of the collateral damage a course of antibiotics can have. A new era of developing the ‘good microbes’ themselves as therapeutic agents, using them to treat disease, or to recolonise damaged intestinal ecosystems, beckons. New drugs may take the form of next generation probiotics or whole microbial community faecal transplants, or even postbiotics, but the common feature is that they are derived from the abundance of our important natural gut inhabitants.

 

Children and dogs in a household share gut microbes – and these microbes are modified by a canine probiotic

From longtime family pets to ‘pandemic puppies’, dog ownership is seemingly more popular than ever. In households with children, scientists have found that a pet dog is one of the environmental factors that influences the gut microbiota in early life – but can the microbes that children and dogs share be modified?

A new study from ISAPP president Prof. Seppo Salminen (University of Turku, Finland) and colleagues recently explored the impact of a household dog on children’s gut microbiota, before and after the dogs were given a canine probiotic. Not only did the gut microbiota of dogs and children in the same household share features in common, but also the gut microbes of both shifted after dogs received a probiotic.

The study, which was part of a larger investigation, looked at families with at least one member who had allergic disease. Thirty-one of the families in the current study had dogs, and 18 families (the control group) did not. From each household, the fecal microbiota of one child (aged 5 or under) was tested. The fecal microbiota of the dogs was tested, and further, they received either a probiotic containing 3 canine-derived strains, or placebo.

The data supported previous observations that dogs and children share gut microbes: the children living with dogs had a distinct fecal microbiota composition. The most striking microbiota differences were a higher abundance of Bacteroides and short-chain fatty acid producing bacteria.

Moreover, when the household dogs were given a probiotic, both the dogs and the children living with them showed a gut microbiota shift, with a reduction in Bacteroides. (The exact probiotic strains were not tracked in the feces of either the dogs or the children.)

Were the changes beneficial? It’s not certain, since health outcomes in the children were not part of the study. But these findings provide more evidence for the effect of home environments and pets on the gut microbiota of children, and highlight the modifiability of both the dog’s and children’s gut microbiota. The ability to modify a child’s gut microbiota is of particular interest in the early years, when gut microbiota / immune interactions have the potential to shape health through the lifespan.

The study authors conclude, “Our promising data invite the idea that the compositional development of the gut microbiota in children is potentially modifiable by indirect changes in household pets and justify the further search of novel modes of intervention during critical period when the scene is set for the consolidation of the child later health.”

How some probiotic scientists are working to address COVID-19

By ISAPP board of directors

With the global spread of COVID-19, the scientific community has experienced an unusual interruption. Across every field, many laboratories are temporarily shuttered and research programs of all sizes are on hiatus. Principal investigators around the world are doing their part to keep their students and local communities safe, and many are donating lab safety equipment to medical first responders who urgently need it.

In this global circumstance of research being put on hold, it is enlightening to consider what some scientists in the fields of probiotics, prebiotics, and fermented foods are working on—or proposing—in the context of understanding ways to combat viral threats. These individuals are rising to the scientific challenge of finding effective ways to prevent or treat viral infections, which may directly or indirectly contribute to progress against SARS-CoV-2.

Here, ISAPP shares words from some of these scientists—and how they have connected the dots from probiotics to coronavirus-related work with potential medical relevance.

Prof. Sarah Lebeer, University of Antwerp, Belgium: Relevance of the airway microbiome profile to COVID-19 respiratory infection and using certain lactobacilli to enhance delivery or efficacy of vaccines

Could the microbes in our upper and lower airways play a role in how we respond to the virus? Significant individual differences exist in the microbes that are prevalent and dominant in our airways. Lactobacilli are found in the respiratory tract, especially in the nasopharynx. They might originate there from the oral cavity via the oronasopharynx, but we have found some strains that seem to be more adapted to the respiratory environment, for example by expressing catalase enzymes to withstand oxidative stress. Currently we have a Cell Reports paper in press that shows certain lactobacilli are more prevalent in the upper respiratory tract of healthy people compared to those with chronic rhinosinusitis. Further investigation of one strain found in healthy people showed it inhibited growth and virulence of several upper respiratory tract pathogens. Our work on other viruses shows that certain lactobacilli can even block the attachment of viral particles to human cells. This raises the possibility that lactobacilli could be supplemented through a local spray to help improve defenses against the inhaled virus. Based on these data, we are initiating an exploratory study with clinicians and virologists on whether specific strains of lactobacilli in the nasopharynx and oropharynx could have potential to reduce viral activity via a multifactorial mode of action, including barrier-enhancing and anti-inflammatory effects, and reduce the risk of secondary bacterial infections in COVID-19.

Another line of exploratory research from our lab pertains to the delivery or efficacy of SARS-CoV-2 vaccines. Currently, many groups are rapidly developing vaccines, which predominantly use the viral spike S protein or its receptor-binding domain as antigen to induce protective immunity. We are exploring the potential of specific strains of lactobacilli with immunostimulatory effects as adjuvants for intranasal SARS-CoV-2 vaccination, or the potential of a genetically engineered antigen-producing organism for vaccine delivery.

At this year’s virtual ISAPP annual meeting, Dr. Karen Scott and I will also be leading an ISAPP discussion group called “How your gut microbiota can help protect against viral infections”. We will discuss previous work that has shown bacteria can have anti-viral effects. For many years, our colleagues, Profs. Hania Szajewska and Seppo Salminen, have studied a different virus, namely rotavirus, that causes acute diarrhea in children, and have found that Lactobacillus rhamnosus GG (new taxonomy Lacticaseibacillus rhamnosus GG) binds rotavirus and disables it, thereby blocking viral infection/multiplication. This may explain why this probiotic reduces the incidence and duration of acute diarrhea in children. Similar findings have been reported for specific probiotics and prebiotics and prevention of upper respiratory tract infections.

Prof. Rodolphe Barrangou, North Carolina State University, USA: Engineering probiotic lactobacilli for vaccine development

Between NC State University and Colorado State University (CSU) there is a historical collaborative effort aiming at engineering probiotics to develop novel vaccines. The intersection of probiotics and antivirals is the focus here with expressing antigens on the cell surface of probiotics to develop oral vaccines. The CSU infectious diseases center is very much fully operational and focused on COVID-19 now, and we recently received a research exception to open our lab for two individuals assigned to this NIH-funded project, and pivot our rotavirus efforts here to coronavirus. We are actively engineering Lactobacillus acidophilus probiotics expressing COVID-19 proteins to be tested as potential vaccines at CSU in the near future, as progress dictates.

Prof. Colin Hill, University College Cork, Ireland: The microbiome as a predictor of COVID-19 outcomes

We have recently proposed a project to examine oral and faecal microbiomes to identify correlations/associations between COVID-19 disease severity and individual microbiome profiles. If funded, we propose to analyse bacterial and viral components of the microbiome from three body sites (nasopharyngeal swabs, saliva, and faeces) in 200 donors and mine the data for biomarkers of disease risk and clinical severity. We will use machine learning to identify microbiome signatures in patients who contract the virus and remain asymptomatic, those who develop a mild infection, or those who have an acute infection requiring admission to an intensive care unit and intubation. This will enable microbiome-based risk stratification of subjects testing positive, and appropriate clinical management and early intervention, and prioritization of subjects for receiving an eventual vaccine.

Dr. Dinesh Saralaya, Bradford Institute for Health Research, UK: A live biotherapeutic product for targeted immunomodulation in COVID-19 infection

The COVID-19 pandemic presents an unprecedented challenge to our healthcare systems and we desperately require the rapid development of new therapies to ease the burden on our intensive care units. As well as its appropriate mechanism of action (targeted immunomodulation rather than broad immunosuppression), the highly favourable safety profile of MRx-4DP0004 makes it a particularly attractive candidate for COVID-19 patients, and may potentially allow us to prevent or delay their progression to requiring ventilation and intensive care.

The trial is a Phase II randomised, double-blind, placebo-controlled trial to evaluate the efficacy and safety of oral Live Biotherapeutic MRx-4DP0004 in addition to standard supportive care for hospitalised COVID-19 patients. Up to 90 subjects will be randomised 2:1 to receive either MRx-4DP0004 or placebo (two capsules, twice daily) for 14 days. The primary endpoint is change in mean clinical status score as measured by the WHO’s 9-point Ordinal Scale for Clinical Improvement, while secondary endpoints include a suite of additional measures of clinical efficacy such as need for and duration of ventilation, time to discharge, mortality, as well as safety and tolerability. The size and design of the trial are intended to generate a meaningful signal of clinical benefit as rapidly as possible.

Drs. Paul Wischmeyer and Anthony Sung, Duke University School of Medicine, USA: Probiotics for prevention or treatment of COVID-19 infection

We are planning several randomized clinical trials of probiotics in COVID-19 prevention and treatment. These trials are based on multiple randomized clinical trials and meta-analyses that have shown that prophylaxis with probiotics may reduce upper and lower respiratory tract infections, sepsis, and ventilator associated pneumonia by 30-50%. These benefits may be mediated by the beneficial effects of probiotics on the immune system. The Wischmeyer laboratory and others have shown that probiotics, such as Lactobacillus rhamnosus GG, can improve intestinal/lung barrier and homeostasis, increase regulatory T cells, improve anti-viral defense, and decrease pro-inflammatory cytokines in respiratory and systemic infections. These clinical and immunomodulatory benefits are especially relevant to individuals who have developed, or are at risk of developing, COVID-19. COVID-19 has been characterized by severe lower respiratory tract illness, and patients may manifest an excessive inflammatory response similar to cytokine release syndrome, which has been associated with increased complications and mortality. We hypothesize that probiotics will directly reduce COVID-19 infection risk and severity of disease/symptoms. Thus, we are proposing a range of trials, the first of which will be:

A Randomized, Double-Blind, Placebo-Controlled Trial of the PRObiotics To Eliminate COVID-19 Transmission in Exposed Household Contacts (PROTECT-EHC). Objective: Prevent infection and progression of illness in household contacts/caregivers of known COVID-19 patients exposed to COVID-19 (who have a >20-fold increased risk of infection). We will conduct a multicenter, randomized, double blind, phase 2 trial of the probiotic Lactobacillus rhamnosus GG vs. placebo to decrease infections and improve outcomes. This trial will include weekly collection of microbiome samples from multiple locations (i.e. fecal, oral). This trial will utilize a commercial probiotic, delivering 20 billion CFU of Lactobacillus rhamnosus GG, and placebo.

We are currently developing protocols to study prevention and treatment of COVID-19 in a range of other at-risk populations including: 1) Healthcare providers; 2) Hospitalized patients; 3) Nursing home and skilled nursing facilities workers. We are seeking additional funding and potential collaborators/trial sites for this work, and encourage interested funders and collaborators to reach out for further information or to join the effort at: Paul.Wischmeyer@nullduke.edu and also encourage you to follow our progress and our other probiotic/microbiome work on Twitter: @paul_wischmeyer

Prof. Gregor Reid, University of Western Ontario, Canada: Documenting anti-viral mechanisms of certain probiotic strains

While our institute is now studying the cytokine storm in COVID-19 patients, the closure of my lab has meant I have turned to surveying the literature: Prof. Glenn Gibson and I have a paper published in Frontiers in Public Health stating a case for probiotics and prebiotics to help ‘flatten the curve’ and keep patients from progressing to severe illness. There is good evidence that certain orally administered probiotic strains can reduce the incidence and severity of viral respiratory tract infections. Mechanistically this appears to be, in part, through modulation of inflammatory responses similar to those causing severe illness in COVID-2 patients, and antiviral activity — which has not been shown against SARS-Co-V2 but has been documented against common respiratory viruses, including influenza, rhinovirus and respiratory syncytial virus. Improving gut barrier integrity and affecting the gut-lung axis may also be part of these probiotics’ mechanism of action. At a time when drugs are being tried with little or no anti-COVID-19 data, probiotic strains documented for anti-viral, immunomodulatory and respiratory activities should be considered for clinical trials to be part of the armamentarium to reduce the burden and severity of this pandemic.

Rapid, collaborative effort

As the world waits in ‘lockdown’ mode, continued scientific progress for coronavirus prevention or treatment is critically important. ISAPP salutes all probiotic and prebiotic scientists who are stepping up to pursue unique solutions. Addressing the important research questions described above will require a rapid collaborative effort, from obtaining ethical approval and involving medical staff to collecting the samples, to recruiting participants as well as experts to process and analyze samples. All of this has to be done in record time – but from our experience of this scientific community, it’s definitely up to the challenge.

seppo

Welcome Seppo Salminen – ISAPP’s New President

An interview with Prof. Seppo Salminen

ISAPP President 2018-2021

 

1) What are your goals as the next president of ISAPP? 

My goal is to work together with the board and the members to advance excellence in the science of probiotics and prebiotics and to share research and conclusions with as wide an audience as possible. It is also my goal to leverage ISAPP’s scientific  expertise to work with organizations to promote  evidence-based applications of probiotics and prebiotics to advance health and well-being of people.

2) What do you hope to see the organization accomplish during your tenure?

ISAPP is engaged now in North America, Europe and Asia so maybe we can be really be global and reach out to South America and  connect with researchers in Africa as we have done with Professor Reid earlier. I would like to work toward common goals with more industrial, scientific and regulatory experts from different parts of the world.

3) What changes do you foresee in the field of probiotics and prebiotics in the next few years?

 I foresee rapid development in probiotics and prebiotics. There will be novel microorganisms developed and novel sources of prebiotics and this direction leads to challenges in safety evaluation and efficacy demonstration  as well as communication of the results to larger audiences.

4) How did you originally become involved in ISAPP?

I was originally invited to one ISAPP meeting, then to the next one, then to the third one and at the end was invited to be a member of the board, which I considered a special honour!

5) Which ISAPP meeting was your favorite so far?

They all have been excellent, but some I remember (each for different reasons) are the ones in Barcelona, New York, Chicago and Berkeley – and now Singapore. Of course, the one in Turku, Finland as well – when you help organize a meeting like that you certainly remember even on a minute-by-minute basis.

Thank you Prof. Salminen and welcome!

free_webinar_gut

Free Webinar: Why is everybody talking about gut microbiota?

Coming up on Thursday, June 28th ISAPP Board Member Professor Glenn Gibson will be featured in a free webinar discussing gut microbiota. Hosted by the British Nutrition Foundation, the webinar will examine what we know about gut microbiota and what remains to be explored. Research on gut microbiota has indicated the gut has a role in metabolism, immunity, and more!

The British Nutrition Foundation says “This free webinar aims to increase understanding of the gut-brain axis and the evidence for the role of gut microbiota in metabolic health and immunity. We are absolutely delighted to have world renowned experts speaking in our programme including:

  • Professor Ian Rowland (University of Reading)
  • Professor Ted Dinan (University College Cork)
  • Professor Glenn Gibson (University of Reading) “

 
Find out more information and register for the webinar here.

probiotics association of india

ISAPP Goes to India

By Mary Ellen Sanders PhD and Dan Merenstein MD

ISAPP sent two key-note speakers to the Probiotics Association of India meeting, held Feb 16-17 in New Delhi. Prof. Dan Merenstein MD spoke on “Evidence for clinical indications: how do probiotics measure up?” and Dr. Mary Ellen Sanders addressed “Is it time for live cultures to be included in official dietary recommendations?”  Dr. Merenstein also gave a second talk on an ISAPP-supported project:  the evidence that probiotic consumption can reduce antibiotic utilization. This is the 3rd PAi meeting that ISAPP has supported through speaker sponsorship.

The meeting featured talks on synbiotics to prevent late-term sepsis (Pinaki Panigrahi), the impact of diet on the Indian gut microbiome (Yogesh Shouche), autism (Sheffali Gulati) and 10 selected student/young investigator presentations on diverse microbiota/probiotic studies. Because of the high quality student presentations, judges were unable to choose the best to award prizes. The solution: all 10 presentations were awarded 5000 INR, supported by Prof. Pinaki Panigrahi’s Center for Global Health and Development. A poster session and original probiotic-themed drawings (see below for one submission) were also presented.

Dr. Sanders also spoke on “The contribution of probiotics to health” in an event held February 15 sponsored by the Gut Microbiota and Probiotic Science Foundation (India). This event was attended by ~150 professionals in nutrition, medicine and microbiota/probiotic research.

Of course, the trip was not all work. Below, Mary Ellen takes a selfie with her new elephant friend, Sampa.

probiotic poster

Probiotics and Good Gut Health. An artistic interpretation by a student, Simranjeet Singh.

elephant india

Mary Ellen Sanders takes selfie with Sampa, a 62-year old Asian elephant.

news probiotics UK

ISAPP works to have evidence-based usage of probiotics to prevent antibiotic-associated diarrheoa implemented in UK

January 12, 2018. Antibiotics are amongst the most commonly prescribed drugs in UK hospitals. However, as well as treating infection they can cause disruption to the gastrointestinal microbiota. This can lead to the relatively common side-effect of antibiotic-associated diarrhoea (AAD) which often delays discharge. More concerning is that a disruption to the normal gut microbiota can lead to reduced resistance to opportunistic pathogens such as Clostridium difficile, leading to C. difficile infection, a potentially severe or fatal infection. Based on the available evidence, probiotics are a safe and effective adjunct to antibiotics to reduce the risk of developing AAD and for the primary prevention of CDAD. The International Scientific Association of Prebiotics and Probiotics has reviewed available data and supports several published assessments, which recommend probiotics as adjunctive therapy for prevention of AAD and CDAD.

This effort was led by Dr. Claire Merrifield BSc MBBS PhD, Speciality Registrar in General Practice, St. Mary’s Hospital, Imperial College Healthcare Trust, Imperial College London and Prof. Daniel Merenstein, MD, Department of Family Medicine, Georgetown University Medical Center and ISAPP Board Member and Treasurer.

Read full recommendation here, which will be sent to NICE and Public Health England.

baby crying colic

ISAPP Digs Deeper into Evidence on Probiotics for Colic with New Meta-Analysis

January 3, 2018.

Evidence exists for gut microbiota differences between infants with and without colic, with one probiotic strain of particular interest therapeutically for colicky infants: Lactobacillus reuteri DSM17938. Discussion groups convened at the 2014 and 2016 ISAPP meetings, both led by Prof. Michael Cabana MD MPH of University of California, San Francisco, and member of ISAPP’s board of directors, focused on the existing randomized, controlled trials and how they might inform medical recommendations.

The discussion group at the 2014 ISAPP meeting in Aberdeen Scotland resulted in a paper describing the individual patient data meta-analysis (IPDMA) protocol, which was published in BMJ Open.  The 2016 ISAPP meeting in Turku Finland culminated in the publication of this IPDMA in the journal Pediatrics: Lactobacillus reuteri to treat infant colic: a meta-analysis. Dr. Valerie Sung, Royal Children’s Hospital, The University of Melbourne and Murdoch Children’s Research Institute, was lead author of this paper, whose coauthors included a team of 11 other experts spanning three continents.

This high quality meta-analysis used individual patient data rather than group means to get a more accurate picture of the efficacy of the probiotic. The paper concluded that L. reuteri DSM17938 is effective and can be recommended for breastfed infants with colic. However, data are lacking for efficacy in formula-fed infants.

“Any single randomized clinical trial involves a great deal of time and resources from investigators, institutions and most importantly, patients. By working together, our team was able to combine data to learn more about the effects of L. reuteri DSM 17983 on the treatment of infant colic. This analysis is a great example of the power of close international collaboration by clinical investigators.”

Related:

Probiotics for Colic—Is the Gut Responsible for Infant Crying After All? (Open access through Jan 10, 2018)

https://www.mcri.edu.au/news/hope-parents-children-colic