probiotics larson photo

Probiotics: the importance of the complete product

February 11, 2018. By Dr. Olaf F.A. Larsen, Assistant Professor (0.2 FTE) at Athena Institute, VU University Amsterdam, The Netherlands, and Science Manager at Yakult Netherlands.

Probiotics are, according to the WHO and later updated by a consensus panel convened by ISAPP, defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”. Most scientific literature ties probiotic properties to individual strains, although evidence suggests that some health benefits may generalize to the species or genus level. Another important factor in how a probiotic performs is the type of matrix (e.g., a milk drink) that carries the probiotic. Indeed, many successful commercial probiotic products are largely defined by both the probiotic contained and the final product format. A plethora of probiotic products are available, ranging from fermented milks/yogurts, cereal products, juices and freeze-dried products (powders and pills). Some products claim to be probiotic but lack substantiation, such as “probiotic” pizzas and mattresses. It is likely that the probiotic properties are not solely determined by the probiotic strain itself, but also by the harbouring matrix. Hence, in order to fully understand the parameters that drive functionality of a specific probiotic, the total product should be evaluated.

Recently, the influence of the matrix on measures of probiotic functionality was reviewed. The data suggest that the matrix impacts several parameters, including number of viable probiotic microorganisms present in the product through shelf life and survival of the probiotic through the gastrointestinal tract. As an example, the number of viable microorganisms in the product as a function storage time can be profoundly different depending on the combination of probiotic strains and matrices used. Some products in which lyophilized probiotics are incorporated into a peanut butter matrix can have storage times up to 50 weeks. Whey proteins present in milk may improve gastrointestinal tract survival. Therefore, one should be aware that it is likely that viability of the probiotic will be impacted by the carrier matrix.

Another way that matrix can be important is through delivery of additional beneficial substances. For example, milk products contain various vitamins, calcium and high quality protein. In the case of a fermented probiotic product, the fermentation process may yield functional substances such as antihypertensive peptides. These effects can be considered as “additional benefits” of the matrix, beyond the impact of matrix on probiotic survival both in the product and in your body.

The body of scientific evidence falls short, however, of proving the importance of matrix on health endpoints. For a given amount of probiotics delivered, we lack comparative studies that prove that the end-benefit of one carrier matrix is better than another. Many supportive studies suggest that this will be the case, but until head-to-head human studies are conducted, we don’t know for sure.

Given the impact the matrix exerts on probiotic survival, and the possible effect on probiotic effectiveness, keep in mind the importance of efficacy studies conducted on the complete probiotic product. We need more research to fully understand the role of matrix on probiotic effectiveness, but the strongest evidence comes from studies conducted on the complete probiotic product.

Figure: Determinants of probiotic product parameters (adapted from Flach et al. 2017). Mark B. van der Waal is gratefully acknowledged for producing the artwork.

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For another perspective see Does the delivery format affect probiotic efficacy?, March 28, 2018 by Mary Ellen Sanders.


ISAPP Board Members, Professors Michael Cabana MD MPH and Seppo Salminen PhD, will be participating in the 4th Annual Prebiotics and Probiotics in Pediatrics conference in Bari, Italy April 12-14, 2018. Prof. Cabana will be chairing a panel on colic and will discuss findings from a meta-analysis of L. reuteri as an intervention for colicThis meta-analysis, published December 2017, was the outcome of discussion groups convened at the 2014 and 2016 ISAPP meetings, both led by Prof. Cabana of University of California, San Francisco.

Prof. Salminen will share his decades of knowledge of probiotics, colonizing microbiota and pediatric applications in his presentation titled “Bacteriome and Friends.”

Don’t miss the 4th Annual Prebiotics and Probiotics in Pediatrics conference, which is a unique opportunity to meet major experts in the field while learning the most updated basic and clinical research on prebiotics and probiotics for the developing human. The three-day meeting will cover the major novelties in pediatric gastroenterology, obesity, allergy, nephrology, neonatology and the new scenario on gut-brain communication.

Talking Science with ISAPP’s Science Translation Committee

By Christopher Cifelli, PhD, VP of Nutrition Research, National Dairy Council.

Communicating with others is an essential part of everyday life. We are constantly sharing information about a variety of topics with friends, family, and even strangers. Most of the time the interaction is easy and natural – and sometimes even fun. But, have you ever talked to a scientist or asked a scientist a question?

Scientists love to talk about their research. And, other scientists want other to know about their research. They enjoy expounding on the minute details of their work and can spend hours on the littlest detail. That is one trait that makes a scientist effective – the attention to detail needed to posit hypotheses and then experimentally test them in controlled, thought-out manners. Scientists can talk to other scientists easily – but, ask some of them to explain their work to the average person and it doesn’t always go so well.

ISAPP is composed of scientists that are world-renowned experts on probiotics, prebiotics, and fermented foods. And, like other scientists, ISAPP wants others to know and understand these complex topics so that they can make informed decisions that may benefit their health. The question was – how does ISAPP do that? The answer: focusing on effectively translating the science. I offered ISAPP my leadership of a new committee to take on this task. ISAPP formed the Science Translation Committee nearly 3 years ago with a goal of taking complex scientific topics and making them easy to understand for consumers and health professionals. The result of this effort has been the development of numerous infographics, blog posts, and informational videos that translate years of research into easily digestible nuggets of information that people can use. The most recent infographic focused on dispelling some common myths about probiotics – because, who doesn’t like some myth busting!

Effective science communication is essential – essential because it can help people understand the complex and enable them to make choices that can benefit their overall health. ISAPP – which is grounded in science – will continue to be the voice of probiotic and prebiotic science and work to help people understand these fun and interesting topics. So, check out our website and our resources and start learning!

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Global FoodOmics: A Crowd-Sourced Window Into Microbes In Our Foods

January 25, 2018. By Mary Ellen Sanders, PhD , Dairy & Food Culture Technologies

Among the factors under our control, diet may be the most important determinant of our gut microbiota. Observations from the American Gut Project suggest that foods containing live microbes increase fecal bacterial diversity, which is generally associated with a healthy gut.

An initiative, Global FoodOmics, was launched earlier this year at the University of California San Diego under the auspices of the American Gut Project to learn more about bacteria in foods and the small molecules they produce. Dr. Julia Gauglitz is the project manager. Food samples (over 2000 have been collected to date) have been analyzed for their small molecule composition and will be tested by 16S rDNA sequencing to determine the bacterial species present. Although currently in its early stages, the aim for this project is to inventory the vast different foods consumed by people around the world.

Although many fermented foods (beer, bread, wine, kefir, many cheeses and others) rely on yeast or molds as fermentation or ripening agents, this project will aim to detect bacterial DNA, but these DNA approaches cannot distinguish between life and dead bacteria.  Labels and other descriptors accompanying submitted food samples may help determine if the species detected are likely to be alive. Fermented foods that retain live bacteria are more likely to influence our colonizing microbiota.

The small molecules being assayed are not limited to the ones produced by microbes. They may be due to microbial growth in the food (by food fermentation microbes or perhaps by spoilage or food poisoning microbes), may be innate to the food, or may be intentional or incidental (e.g., pesticides) additives to foods.

The intent is to turn Global FoodOmics into a crowd-sourced project. It will join the American Gut Project as an avenue for citizens to directly participate in science and enable the project to make all of the data publically available to other researchers and clinicians.

It is notable that this project is not the first attempt to understand the microbial components of food. Food microbiologists for decades have been assaying foods for microbes used to produce food, responsible for food spoilage and linked to food poisonings.  Recently, Prof. Bob Hutkins, University of Nebraska, on behalf of the International Scientific Association for Probiotics and Prebiotics (ISAPP) and with support from the National Dairy Council, embarked on a project to learn the state of knowledge about levels of live microbes in fermented foods. They dug into the published literature and emerged with “A survey of live microorganisms in fermented foods”, In Press at Food Microbiology. This paper gives us a summary of what is known about populations of live microbes in fermented foods, information that is very useful for people wanting to add live microbes to their diet.

Another effort to understand microbes in foods is the Consortium for Sequencing the Food Supply Chain, a partnership between IBM Research and Mars Inc. This project, focused on food safety, aims to develop a baseline of normal microbial communities in foods.

Both Global FoodOmics and the Consortium for Sequencing the Food Supply Chain will leverage modern DNA sequencing technologies to allow us better understand the microbes associated with foods. Global FoodOmics is the first project to understand the microbes and molecules in foods, by pairing small molecule metabolomics measurements with rDNA sequencing.

blog reid elderly

Do dietary effects on gut microbiota promote health in older individuals? Reid and colleagues gain insights into microbiota composition across the lifespan

January 22, 2018. By Dr. Gregor Reid

ISAPP Board of Directors member Dr. Gregor Reid recently co-authored a cross-sectional study in a cohort of over 1000 very healthy Chinese participants from 3 to over 100 years of age in order to gain insights on ‘healthy’ microbiota composition and whether this changes with age. Using next-generation sequencing (Illumina MiSeq platform) and large-scale compositional data analysis techniques, the study demonstrated that there was very little difference in the fecal microbiota composition of individuals between the around 30 years of age and around 100—as long as the individuals were extremely healthy.

The concept of consuming live microorganisms that offer a benefit to the host (probiotics), or a substrate that is selectively utilized by host microorganisms conferring a health benefit (prebiotics), to promote health in aging populations is becoming more popular. However, it is not currently known what constitutes a ‘healthy’ gut microbiota composition, or what specific prebiotic/probiotic might help establish it.

Discussing the study results in a Reddit Ask Me Anything session, Reid explains, “It is hard to pin down outcomes to one factor such as food, and which components of those foods are critical, but seeing the super-healthy elderly having the same microbiota profile as the super-healthy young adult might make us see if some food practices from 75 years ago have returned.”

Although the study design (cross-sectional) does not allow for a cause and effect relationship to be established, the results may signify that the similarity of gut microbes across ages is a consequence of an active lifestyle and good diet—in contrast with previous hypotheses that aging per se affected gut microbiota composition. Based on these findings, it is reasonable to hypothesize that reestablishing a dysbiotic microbiota composition in older adults, to mirror that of a 30-year-old, may promote health. Moreover, the results offer an established baseline microbiota composition by which other cohorts with chronic or acute disease may be compared.


How often do you hear information about probiotics that is just plain wrong? Too often write-ups on probiotics in blogs, websites, articles written by the lay press, and even sometimes in scientific journals is not true to the science. The latest ISAPP infographic corrects several common misconceptions about probiotic dose, sweetened probiotic yogurts, fermented foods, and more. In doing so, this infographic furthers ISAPP’s core values of stewardship, advancing the science and education.

This resource was developed by ISAPP’s Science Translation Committee and approved by  the ISAPP board of directors.

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Resilience as a measure of health: implications for health claims for foods

January 16, 2018. By Mary Ellen Sanders PhD, Sylvie Binda PhD, Seppo Salminen PhD, Karen Scott PhD

Demonstrating health benefits for healthy people is a challenge faced by those attempting to communicate claims on a health promoting food. Foods, in many global regulatory frameworks, are intended for the general population. Therefore, any benefits ascribed to them, the logic goes, must be demonstrated in the generally healthy population.

An old concept has new-found notoriety in the context of offering an approach for establishing health benefits for healthy people. It is the concept of resilience. In an ecological sense, resilience refers to the ability of an ecosystem to withstand perturbation and continue normal function, i.e. maintain homeostasis. In the context of human physiology, resilience enables a host to remain healthy even when exposed to a stress, or to recover from a stress faster. A variety of external challenges such as drugs, pathogens, emotional stress, poor diet among others, may perturb normal physiological function or disrupt the gut ecosystem. Individuals more able to maintain stability of physiological functions when exposed to such challenges would be healthier than those who cannot maintain stability.  Thus, a food would be considered to have a beneficial effect if it could increase the resilience of the consumer to a challenge.

This concept was described in an EFSA guidance document on biological relevance of data in scientific assessments:

“When subject to a disturbance, a biological system enters in a transient state: a process variable has been changed and the system has not yet reached steady state. Some systems, including humans, have the capacity to regulate their internal environment and to maintain a stable, relatively constant condition of properties; it is called ‘homeostatic capacity’. Resilience represents the amount of disturbance that can be absorbed by a system before the system changes or loses its normal function, or the time taken to return to a stable state, within the normal operation range following the disturbance…” [Reducing] “homeostatic capacity … might be detrimental, whereas increasing the capacity could be beneficial.”

This concept aligns with the definition of ‘health’, which includes the ability to adapt to the environment.

Resilience of gut microbiota

This concept of resilience can be applied to the human microbiota as an ecosystem. Once established in early childhood, our colonizing microbiota reaches a relatively stable state. Although brief fluctuations occur, especially in relation to daily diet and medicines used, the microbial ecosystem of a healthy adult provides relatively stable functionality.  Disruption of the microbiota by repeated stressors can be associated with poorer health. There seems to be a solid rationale that the ability of the colonizing microbiota to resist, or recover quickly from, perturbations reflects a person’s ability to remain healthy. The microbiota stability may be indicated in either populations of bacteria or their metabolic output.

Homeostasis and health: a statistical approach

“A statistical approach to measuring improved health was proposed by Dr. Dan Tancredi at the 2010 ISAPP meeting. It is reprinted here from: Sanders, et al. 2011. Health claims substantiation for probiotic and prebiotic products. Gut Microbes 2:3, 1-7.

An approach to measuring improved health may be to measure homeostasis, as suggested by D. Tancredi. From a statistical point of view, if an intervention were able to minimize the variation around the mean for a specific measure (even in the absence of changing the mean; Fig. 1), it could be a reflection of improved health, assuming a biological rationale exists that tighter control of the parameter is physiologically advantageous. In other words, lessening the fluctuation around an individual’s biomarker could be interpreted as contributing to improving health. This novel idea emphasizes the importance of homeostasis as a focus of studies on health, and provides a rationale based in solid statistical theory as a way to measure this.

One challenge to demonstrating the value of this approach is to identify appropriate biomarkers that could be studied. The following properties would be important to a relevant biomarker for homeostasis:

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  • maintaining moderate levels of the biomarker is associated with good health;
  • high or low values are associated with ill health;
  • biomarker levels in the same person can fluctuate over time; and
  • reducing the magnitude or duration of such fluctuations in healthy people is considered desirable (Fig. 2).

Such a biomarker could be an individual endpoint or be formed as a ratio of two other biomarkers, when maintaining the same relative amounts of the two component biomarkers would be desirable.

Assuming a biomarker with the above properties is available, it could be used as the outcome measure in a randomized controlled trial to provide evidence that the experimental food is able to improve the maintenance of health in humans. Statistically, the trial would be set up to address the hypothesis that the experimental substance is associated with lower variation in biomarker levels, compared to the control arm, in subjects who were healthy at baseline. Such a trial would be able to use information on within-person variations in biomarker levels, even those who did not become ill. Partly as a result of the more efficient use of study data, such a trial would require far fewer subjects than an intervention that instead addressed the hypothesis that treatment is associated with fewer healthy persons becoming ill.

A mounting understanding of the value of stability of the colonizing microbial communities makes this endpoint an attractive one to consider. Perturbation of gut microbiota is associated with intestinal dysfunction, as illustrated during antibiotic treatment. Specific probiotics have been shown to promote a quicker rebound from antibiotic-induced microbiota disruption, including a study on Lactobacillus rhamnosus GG (LGG) (Cox et al. 2000). This paper concludes ‘…that a key mechanism for the protective effect of LGG supplementation on the subsequent development of allergic disease is through the promotion of a stable, even and functionally redundant infant gastrointestinal community.’

However, it would be useful to define additional biomarkers that would be appropriate targets for this type of investigation.

In pediatric nutrition, the measurement of metabolic homeostasis has become a standard approach when developing infant formulas (Heird, 2005).  The concept of homeostasis as a model to distinguish between foods (including food supplements) and medicinal products was explored by the Council of Europe (2011), and is an interesting correlate to the above hypothesis.”


The recent recognition by EFSA that maintenance of homeostasis is a valid measure of health provides an opportunity to apply this concept to validate health benefits of specific foods and food ingredients. Stability of microbial populations, microbial metabolism or host physiological readouts could be measured to reflect the concept of resilience. Since there is no definitive composition of a ‘healthy human microbiota’, a more reasonable target for measuring positive impacts of a probiotic on the microbiota would be reflected not in absolute levels of specific microbes but in the ability of a specific probiotic or prebiotic to bolster the resilience of the microbiota.



Council of Europe. Homeostasis, a model to distinguish between foods (including nutritional supplements) and medicinal products 2008; (Accessed February 24, 2011, at ).

Cox MJ, Huang YJ, Fujimura KE, Liu JT, McKean M, Boushey HA, et al. Lactobacillus casei abundance is associated with profound shifts in theGunderson LH, 2000. Ecological resilience: in theory and application. Annual Review of Ecology and Systematics, 31, 425–439.

EFSA guidance document:  Guidance on the assessment of the biological relevance of data in scientific assessments; July 12, 2017; EFSA Journal 2017;15(8):4970

Heird WC. Biochemical homeostasis and body growth are reliable end points in clinical nutrition trials. Proceedings of the Nutrition Society 2005; 64:297-303.

Huber M, Knottnerus JA, Green L, van der Horst H, Jadad AR, Kromhout D, Leonard B, Lorig K, Loureiro MI, van der Meer JW, Schnabel P, Smith R, van Weel C, Smid H (2011). “How should we define health?” BMJ. 343:d4163.

Sanders, et al. 2011. Health claims substantiation for probiotic and prebiotic products. Gut Microbes 2:3, 1-7; May/June 2011










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.”


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

watch with times they are a-changin quote by bob dylan

The Times They Are A-Changin’ With Probiotics

December 15, 2017. By Prof. Daniel Merenstein, MD, Department of Family Medicine, Georgetown University Medical Center, Washington DC.

I had a surprising encounter a few weeks ago in the clinic. I was caught off guard, had to take a step back and think about what happened. I recommended to my patient that she take a probiotic with the antibiotic I was prescribing. She said to me, “What is a probiotic?” My response was, “A probiotic,” as if it didn’t require any further explanation. It was nearly incomprehensible to me that she didn’t know what a probiotic was and maybe she just didn’t hear me or just didn’t understand me (I tend to speak too fast). But no, she just didn’t know what one was. I then realized how unusual this encounter was.

Something has been a-changing. It hasn’t been a quick process and I am not sure when it changed, but it did. Even just a few years ago when I recommended supplementing a course of antibiotics with a probiotic, people were generally receptive and had a vague idea about probiotics. However we generally had to talk about what probiotics were and how to use them. Fast forward to today and it appears to me that 95% of people respond, “I already take one.” Much more common than hearing “What’s a probiotic?” is to hear, “Of course, you always have to take a probiotic when taking an antibiotic.”

I am currently recruiting for my 8th probiotic clinical trial (PLAY ON). My team has recruited over 1,400 participants for previous studies. We have a system and a great team, but we are having the most difficult time recruiting for this study. I have thought a lot about why and I think it comes down to the times they are a-changin’. When we started on this research path 12 years ago, our research team and the subjects we recruited were excited about probiotics and their potential. But today the public doesn’t see the potential of probiotics; they know probiotics impact the gastrointestinal tract and should be used when taking antibiotics. Therein lies our challenge: to be in our study a subject has to be willing to take the chance of being in the placebo group. That makes little sense to a public that already knows to take a probiotic when on antibiotics.

My first two NIH studies were funded by the National Center for Complementary and Integrative Health, while my current study is funded by the National Institute of Child Health and Human Development. The shift has occurred from complementary, to mainstream. One need no longer attend a microbiome or probiotic conference to hear talks on probiotics; nearly all clinical conferences will now have probiotic talks. I am confident my team will adjust to these changing times but I think more important is how researchers and clinicians adjust. Probiotics are not alternative options anymore, the evidence base is robust and some indications well-studied. The discussions need to shift from, “You should have probiotics on formulary” to specific recommendations of which probiotics should be used for what indications. Similarly when discussing other disease states in the gut (e.g. necrotizing enterocolitis, infantile colic, and irritable bowel syndrome), it is time to take the next step and discuss specific recommendations. I am sure I will see another patient who has never heard of probiotics, but I’m willing to bet that doesn’t happen for many months. More likely, I expect I will be discussing the efficacy of the products my patients are already taking. That is an important change that docs need to think about.

Come gather ’round people
Wherever you roam
And admit that the waters
Around you have grown
And accept it that soon
You’ll be drenched to the bone.
If your time to you
Is worth savin’
Then you better start swimmin’
Or you’ll sink like a stone
For the times they are a-changin’.

Bob Dylan, Nobel Laureate

The Times They Are A-Changin’

Columbia Records, 1964

fermented foods

Fermented foods, health and ISAPP

By Mary Ellen Sanders PhD, Executive Science Officer, ISAPP

It seems that fermented foods have ‘arrived’. Just within the community of ISAPP board members, fermented foods and their importance to health have been a topic of great interest. The idea that adding foods containing live microbes may be sound dietary advice has been reflected in many venues and formats, as seen here:

  • Bob Hutkins:
    • Presented “Health benefits of fermented dairy foods: microbiota and beyond” at 5th YINI Summit (Danone Institute) Fermented Foods and Health: The Intersection of Gut Microbiota and Fermentation Microbes on October 18, 2017.
    • Will convene a discussion group at ISAPP 2018 in Singapore “Taking advantage of fermented foods for health.”
    • Submitted a paper on counts of live microbes in fermented foods “A survey of live microorganisms in fermented foods”
    • Along with lead author Maria Marco and others summarized a discussion group on fermented foods convened at the 2016 meeting of ISAPP in Turku, reflected in this popular Current Opinions in Biotechnology article, Health Benefits of fermented foods: microbiota and beyond.
  • Gregor Reid:
  • Mary Ellen Sanders
  • Seppo Salminen:
  • ISAPP board of directors
    • In 2015, published several comments to the US Dietary Guidelines Advisory Committee, presenting the scientific rational for fermented foods to be part of the US dietary guidelines. See here and here (and for a comment on prebiotic inclusion in dietary guidelines, see here)
    • Oversaw the ISAPP Science Translation committee, which published a consumer-friendly infographic and related materials on Fermented Foods.

ISAPP will continue to work to get this topic recognized by nutrition professionals globally.

probiotics for healthy people infographic

ISAPP releases new infographic: “Probiotics for Healthy People”

November 20, 2017. Probiotics are most commonly studied with for populations with a specific condition—frequent examples include diarrhea, irritable bowel syndrome, and pouchitis. But what kind of evidence exists on probiotics for healthy people?

A new ISAPP infographic gives an overview of what we know about the use of probiotics in healthy individuals. The resource was developed by ISAPP’s Science Translation Committee and approved by  the ISAPP board of directors.

“Studying health benefits in healthy people is a challenge. But there is evidence that probiotics can provide dietary management of some digestive conditions that don’t reach the level of diagnosed disease as well as prevent of some common infectious diseases and. These, and other benefits, are of value to healthy people,” says ISAPP’s Executive Science Officer, Dr. Mary Ellen Sanders. The new infographic  emphasizes it is not necessary to take probiotics to be in good health, but they may serve as a useful addition to a healthy lifestyle.

Research investigating how probiotics can affect healthy individuals through their microbiomes is ongoing in laboratories around the world, and ISAPP continues to track the latest findings.

stethoscope and keyboard

Interpreting Risk Reduction in Probiotic & Prebiotic Clinical Trials

November 2017. By Prof. Michael Cabana MPH MD, Professor of Pediatrics, Epidemiology & Biostatistics and Chief, Division of General Pediatrics, University of California San Francisco.

Over the last few decades there has been a rapid acceleration in the number of published studies and clinical trials focused on probiotic and prebiotic interventions.  One common result that is reported is the change in risk of a condition or outcome after taking a probiotic or prebiotic supplement.  News articles and broadcasts commonly highlight claims in clinical trials (e.g., “this trial suggests a 33% reduction in X…).  However, in a world where news is sometimes transmitted in 140 characters or less, much nuance from a proper clinical trial can be lost. When assessing claims of risk reduction, it is important to evaluate and interpret these results in their proper context.  Here are a few tips.

What type of risk reduction is being reported?

When assessing the claims from a clinical trial, determine whether the claim is being presented as a relative risk reduction or an absolute risk reduction.  Sometimes the report may describe the risk of the outcome or disease directly compared to the normal incidence of the disease (i.e., incidence seen in the control group). This is a report of an absolute risk reduction. For example, if the control group had a 15% frequency of disease X and the probiotic group had a 10% frequency of disease X, then the absolute risk reduction is 5% (15%-10%=5%). Sometimes the report may describe a relative risk reduction, which is the % change between the risk in the probiotic group compared to risk in the control group. If the control group had a 15% frequency of disease X and the probiotic group had a 10% frequency of disease X, then the probiotic reduced your relative risk by 33% ([15%-10%]/15% = 5%/15% = 33%).

Is the risk reduction clinically significant?

If you notice that a relative risk reduction is being reported as statistically significant, you then need to ask yourself if the outcome is clinically significant. It is possible that a very large change in the relative risk reduction may not be clinically important. For example, if a probiotic intervention decreases the relative risk of disease X by 33%., this percentage sounds very impressive. However, if the baseline risk of contracting disease X is only 0.06% (e.g., it is a very rare condition), then the risk after the probiotic intervention is only 0.04% (still very rare, as reflected in the absolute risk reduction of 0.02%). Although the decrease of 33% that is reported as relative risk seems large, if you take into account the baseline risk, you realize that this is not clinically significant. The risk of 0.06% and 0.04% are essentially the same.

When evaluating an intervention, the context of the disease makes a difference. How often is this disease or condition occurring in the population being studied? The problem with reporting a relative risk reduction is that it is easy to overlook how common or uncommon the disease is to begin with.

Look for the “Number Needed to Treat”

One way to better assess the impact of an intervention is to calculate a “Number-Needed-to Treat” (NNT).  The NNT is the inverse of the absolute risk reduction.

From our example above, a 33% relative risk reduction of a condition with a prevalence of 0.06% (e.g., a very rare condition), means that the probiotic intervention had an absolute risk reduction of 0.02%. The NNT would be equal to 1/[0.0002]= 5000. This NNT of 5000 means that you’d need to treat 5000 patients with the probiotic intervention to change the outcome of only one patient.

Take a different scenario. If the disease was much more common (e.g, 9% prevalence) and the relative risk reduction was still 33%, then absolute risk reduction would be 3%. The NNT in this case would be equal to 1/(0.03)=33.3. This NNT of 33.3 means that you’d need to treat only 33 patients with the probiotic intervention to change the outcome of one patient. This treatment is much more likely to be meaningful in the population.

The NNT is a quick way for clinicians to evaluate an intervention to take into account the risk reduction in the context of the baseline risk.


When examining the results from clinical trials, just looking at percentage changes can be deceiving. Unfortunately, relative risk reduction often results in more sensational headlines, so beware of how the press, and even top quality journals, report study results. When assessing the clinical trial results in the context of clinical care, keep in mind how common or rare the disease is. Even a large percentage change may not make a big difference overall in patient outcomes if the initial risk was very low to begin with. Evaluate and interpret clinical trial results in their proper context.

salminen and hutkins at YINI

Fermented Foods in Nutrition & Health

November 2017. Discussed at International Union of Nutritional Sciences (IUNS) Congress session. By Prof. Seppo Salminen, Director of the Functional Foods Forum, University of Turku.

Recently, the Yogurt in Nutrition Initiative (YINI) convened a scientific session as part of the International Union of Nutritional Sciences (IUNS) Congress, held in Buenos Aires from October 22-27, 2017. The session focused on how yogurt and other fermented foods affect the composition and activity of the gut microbiota and health. Lectures covered microbiota development in humans, metabolic effects of yogurt and fermented foods, the role of fermented dairy foods on health, and the role of yogurt and fermented foods in nutritional guidelines

Professor Robert Hutkins and I presented at the YINI session. Dr. Hutkins spoke about “Health benefits of fermented dairy foods: microbiota and beyond” and started by defining the role of microorganisms during food fermentations. He then reviewed current research findings on the impact of fermented foods on the human intestinal microbiota. He also distinguished between the microbes that perform the fermentation and those added specifically as probiotics. Although they are often closely related, they are not the same. Both culture-based and molecular methods have shown that although microbes consumed in fermented foods often survive transit, they rarely persist after consumption has ended. Still, they may be able to modulate functional activity in the gut and, in the case of yogurt bacteria, improve tolerance to lactose.

My presentation was titled “Improving your diet with fermented foods: harmonizing dietary guidelines including fermented milks” and I reviewed the role of yogurt in dietary guidelines and recommendations in different countries along with the regulatory status of yogurt and health claims. The talk focused on existing guidelines in Europe; specifically, the live bacteria in yogurt and lactose intolerance claim approved by the European Food Safety Authority. This claim states that yogurt cultures improve lactose digestion (and tolerance) in individuals with lactose maldigestion. Additionally, I suggested that fermented dairy products should be included in dietary guidelines in a more consistent manner, as recommendations currently vary from country to country. A special focus was also given to an Argentinian social program which provides at present over 200,000 school children with locally produced yogurt with a probiotic to improve their health and well-being.

The role of fermented foods and especially yogurt has gained substantial attention among researchers, clinicians, public health workers, and consumers. In addition to the live organisms present in fermented foods, peptides and other metabolites produced by these organisms may also mediate important health benefits. Thus, cultured dairy foods and other fermented products may have important effects on public health and their consumption should be encouraged.

stool sample for lab

Microbiome Analysis – Hype or Helpful?

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

Since we have realized that we carry around more microbial than human cells, and that these microbial inhabitants are important to maintain our health, searching for the bacterial species that are implicated in causing disease has become the holy grail of microbiology. However, to understand which bacteria are present or absent in a disease state, we first have to understand what constitutes normal. This is hampered by the fact that we are all different – and our microbial communities are also all different. In fact, the faecal bacterial community in samples taken months apart from one person will be identifiable as coming from that specific healthy adult, but the community will be quite distinct from samples from any other healthy adult. In the same way, the microbial community of two individuals suffering from the same disease will be different.

Despite these differences, scientists have managed to establish some facts over the past 15 years. Too many Proteobacteria, which includes Enterobacteria and E.coli, in your large intestine is not generally good news. Firstly, it means that conditions in the large intestine are probably not oxygen-free, as they should be. Secondly, an expansion in these populations usually means a decline in something else – after all food and places to live are finite resources. Bacterial diversity in the adult intestine is also important. The main factor that has been found across many different diseases is that bacterial diversity is lower in diseased individuals than their healthy counterparts. This does not necessarily mean that a low diversity is causing the disease, as various features of the disease (including any antibiotic therapy, inflammation, decreased or increased transit time) may all themselves affect the diversity of the microbiota.

Although scientists have not succeeded in defining a ‘healthy microbiota,’ there is an increasing trend to get your microbiome tested. Microbiome companies are bombarding us with offers to send in a small sample and find out about your gut microbiota, for a price. So, should you?

This really depends why you want to know, and what level of detail of analysis is being offered. Remember the orders of taxonomy? Kingdom, phylum, class, order, family, genus, and species.  Some companies identify the bacteria in your faeces only to the phylum level. This is a taxonomic level above the level needed to differentiate mammals and fish (these are ‘classes’). If you told someone that there were more fish in the Indian Ocean than mammals would this be a surprise? It would be such an expected fact it would be meaningless. This is similar to describing the microbiota at a phylum level – Bacteroidetes numbers versus Firmicutes numbers. Such numbers are meaningless. However, continuing the fish analogy, if you said that there were more mackerel than tuna in the North Atlantic Ocean this becomes a bit more meaningful. The fisherman immediately knows what type of fish he is more likely to catch, and perhaps even which net to use. The same is true of the microbiome. Telling someone that he/she has a lot of Enterobacteria and few Roseburia is actually useful as we know from studies that this represents an abnormal balance of bacteria and something should be done to redress this. Yet the bottom line health consequence of this abnormal balance of bacteria remains to be determined. So getting your gut microbiome sequenced could be useful – depending on what level of information you will receive, and what you are prepared to do about it.

And so we come to the next problem. Having established what your gut microbiota is, how are you going to make it better? And will that make YOU better? At the moment scientists don’t really have a good answer to these questions. Specific prebiotics can certainly be useful to increase the numbers of some bacteria generally assumed to be beneficial – such as Bifidobacterium, Faecalibacterium prausnitzii and even Roseburia species. But it is not really clear what the exact health benefits of such an increase in bacterial numbers would be. Health claims on prebiotics are currently limited to ‘improve intestinal transit’ and ‘lower the glycaemic response’. If you found out that your microbiota had a low diversity, increasing the variety of foods in your diet, in particular the fibre component, could certainly improve this. Our gut microbiota basically relies on our undigested food to survive, so providing a greater amount and more types of food containing fibre and prebiotics will definitely encourage populations of diverse bacteria to expand. In addition to improving digestive health, fibre fermentation by gut bacteria also results in the production of microbial products that have been shown to have health benefits.

So by all means get your gut microbiome analyzed if you want to, but perhaps instead, save your money and just increase your prebiotic and fibre consumption, which will increase levels of the potentially beneficial bacteria that are already there in your gut.

Recommended reading

Why microbiome tests are currently of limited value for your clinical practice

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ISAPP Releases Series of Informational Videos on Probiotics and Health

October 10, 2017. Probiotics are a hot topic—an online search for information yields millions of hits. But how much of this easily-accessible information is scientifically accurate?

The clinicians and scientists serving on the ISAPP Board of Directors constantly receive questions about what’s true when it comes to probiotics and prebiotics. That’s why ISAPP decided to commission a series of four informational videos on probiotics. These videos were overseen by members of our board of directors without input from industry, but industry provided educational grants for their production.

The four new videos focus on these topics:

  • What is a probiotic?
  • Benefits of probiotics
  • Are all probiotics the same?
  • How to choose a probiotic

Watch for the videos to roll out during the month of October 2017! They’ll appear here on the ISAPP website video page.

With our mission to advance scientific excellence in probiotics and prebiotics, ISAPP is committed to helping consumers access science-based information on probiotics and prebiotics. To stay up to date on ISAPP news, please sign up for our monthly newsletter!

ISAPP 2018 Annual Meeting

Open-Registration ISAPP Conference to be held in Singapore, June 2018

The International Scientific Association for Probiotics and Prebiotics (ISAPP) is pleased to announce the opening of registration for its June 2018 international symposium in Singapore— and welcomes all interested participants around the world.

“Typically, ISAPP meetings are open only to invited experts and scientists from member companies,” says ISAPP Executive Science Officer Mary Ellen Sanders. “But in 2018, ISAPP features an open-registration event June 5th and 6th, welcoming all interested in the probiotic and prebiotic fields, including academicians, industry, regulators, and students.”

The 2018 conference will also mark the first time an ISAPP event has been hosted by a country in Asia. In choosing to congregate in Singapore, says Prof. Gregor Reid, the co-chair of this conference and featured speaker, “ISAPP recognizes the first-rate scientific expertise and growing markets in Asian countries.” He adds, “Our 2018 meeting in Singapore will allow us to better engage those in the Asian region while maintaining a top-notch program featuring global scientists.”

The theme of the conference is “Key Scientific Drivers Behind Probiotic and Prebiotic Applications.” Event’s speakers include global thought leaders in probiotic and prebiotic science, including Dr. Liping Zhao (China), Dr. Sarah Lebeer (Belgium), Dr. Glenn Gibson (UK), Dr. Seppo Salminen (Finland), and more. Plenary sessions will cover topics ranging from pediatric health and allergy to prebiotic mechanisms and strategies for health claim substantiation.

Invited experts and member company scientists will congregate on June 7th, after the main conference, for a “Day of Discussion” related to probiotics and prebiotics.

For more information about the conference and to register, see here.

brain-gut relationship illustration

Bugs on the Brain: the Microbiota-Gut-Brain Axis

September 2017. By Eamonn M. M. Quigley, Chief Division of Gastroenterology and Hepatology, Houston Methodist Hospital and Professor of Medicine, Weill Cornell Medical College, Houston, Texas, USA.

We can all remember those instances of diarrhea (or at least frequent bowel movements) and “butterflies” that we suffered before a critical test, interview or presentation. These are examples of stress originating from the brain influencing gut function. Extensive research over the past several decades has revealed that this is a two-way street – the gut constantly signals to the brain, too. This bidirectional channel of communication between the “big brain” in the cranium and the “little brain” (i.e. the enteric nervous system) in the gut came to be referred to as the gut-brain axis. This link relies on neurons of the sympathetic and parasympathetic nervous systems, as well as circulating hormones and other neuromodulatory molecules.

We now understand that mental symptoms of stress, anxiety or depression have a clinical impact on the gut. These include situations where the brain, the gut and their channel of communication, the autonomic nervous system, are affected by the same pathologic process. Parkinson’s disease is a prime example. Indeed, a hypothesis has evolved to suggest that Parkinson’s disease actually originates in the gut and ascends to the brain. Other scenarios include those instances where neurologic symptoms are a consequence of a primarily gastrointestinal pathology. This occurs in malabsorption syndromes when nutrients such as folic acid and B12, which are critical to brain function, become deficient. Finally, and most commonly, are those situations such as irritable bowel syndrome (IBS) where it is widely believed that symptoms result from dysfunction or disturbance somewhere along the gut-brain axis. In some individuals the problem may lie primarily in the gut; in others the main issues may be a distorted representation of gut stimuli in the brain.

Recently the concept of the gut-brain axis has been extended to include the microbiota (the microbiota-gut-brain axis) and tantalizing evidence suggests that bacteria resident in the gut could have an impact on the “big brain”. Indeed, some researchers have raced ahead to suggest that assessing alterations in the microbiome could assist in the diagnosis of a host of neurological disorders and that therapies targeted at the microbiome could play a central role in disorders as diverse as Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis, autism, stroke, depression and drug addiction.

We should remember that the microbiota-gut-brain axis is far from a novel concept as it was clearly described over 60 years ago with research on hepatic coma. Metabolic products of gut bacteria lead to this much feared complication of advanced liver disease and an intervention targeted at the microbiome, namely, the administration of antibiotics, was shown to be dramatically effective. In these pioneering studies the role of bacterial overgrowth in the small bowel by coliforms and other bacteria, which are normally confined to the colon, was found to be important. Subsequently, these same bacteria and the inflammatory response that they evoke have been incriminated in the pathophysiology of another common consequence of chronic liver disease, portal hypertension, as well as in other complications such as spontaneous bacterial peritonitis, systemic sepsis and hemostatic failure. Indeed, there are several manifestations of this tripartite resonance between microbiota, the liver and the central nervous system. Gut health factors such as small bowel bacterial overgrowth, an abnormal microbiota, impaired gut barrier function, a pro-inflammatory state and the appearance in the systemic circulation of neuro-active molecules generated by bacterial metabolism are all postulated to play important roles in the actual pathogenesis of a number of common liver diseases. So what is new?

From the basic science laboratories and a variety of animal models a pretty coherent message has emerged. Firstly, the microbiome can influence brain development, structure and function and lead to changes in cognition and behavior. Secondly, the manipulation of the microbiome – for example, with probiotics – can ameliorate certain brain disorders and reverse impaired function. Thirdly, the inoculation of microbiota samples from individuals with a number of neuropsychiatric disorders into animal models can recapitulate features of the human disease. So far so good.

As always, extrapolation from animal studies to humans is fraught with difficulties: differences between animal and human brains and microbiota, the limitations of animal models of psychiatric and functional bowel disorders, and, above all, the challenges of studying brain function in humans. The good news is that these challenges are being addressed. Researchers are utilizing various technologies that provide dynamic images of brain function in various parts of the brain in response to a variety of situations, stimuli and exposures. These are now beginning to provide evidence that our microbiota can influence brain function and that the gut microbiota might, indeed, be a therapeutic target for patients with disorders such as depression, Parkinson’s disease and autism. Data are preliminary and certainly not at a stage where we can offer diagnostic testing based on a fecal sample or recommend antibiotics, prebiotics, probiotics or fecal microbiota transplantation for a given neuropsychiatric disease or disorder. But watch this space!


Kombucha: Trend or New Staple?

September 2017. By Prof. Bob Hutkins, Khem Shahani Professor of Food Science, University of Nebraska, Department of Food Science and Technology, Lincoln.

This blog post is adapted from a piece published by the Lincoln Journal Star. The article, first published May 4, 2016 and written by Prof. Bob Hutkins, appeared as a response to a reader’s question: “I keep hearing about kombucha… What is this stuff?”

Kombucha (pronounced kom-BOO-chuh) is made by fermenting sweetened tea using a combination of yeasts and bacteria. This mixture of live cultures that starts the fermentation is called SCOBY, short for “symbiotic colony of bacteria and yeast.” The SCOBY takes the form of a gooey mat that can be re-used for each batch or shared with friends.

Kombucha is one of many trendy fermented foods, like kimchi and kefir, that are now found everywhere. No longer just the fare of hipster cafes and posh restaurants, you can find kombucha at your local grocery store—or even at Walmart.

Kombucha’s origins go back at least 2,000 years, to China; the drink gradually spread throughout Asia and Europe. In the U.S., kits for home-brewing kombucha became available to consumers in the early 1990s, and bottled versions soon appeared on grocery store shelves.

Several factors may explain the popularity of kombucha. First, many people like the flavor: uniquely sweet and sour, with a vinegary overtone. Some ethanol (alcohol) may also be present, although commercial products must contain less than the legal limit of 0.5 percent. The fermentation reaction yields carbon dioxide, which gives kombucha a pleasant fizziness. Flavor combinations are endless, from ginger, mango, and blood orange to lavender and cinnamon.

It’s probably the suggested health properties that are most responsible for the kombucha craze. The live cultures in some blends have antimicrobial activity, which may have been valuable in past eras when antibiotics were not available. However, these properties depend on the particular mix of microbes, which varies from batch to batch or brand to brand. Other suggested health benefits range from improved gut health and digestion to treatment of cancer and other diseases. Unfortunately, there is no scientific evidence to support these health claims.

It may be that kombucha is not for everyone—the acidic nature of the drink may not sit well for some people. Microbiologists have also expressed concern that home-brewed kombucha could possibly contain toxin-producing fungi. (See related post on making safe fermented foods at home.)

Nonetheless, there’s no doubt that many consumers are drinking kombucha. Annual sales in the U.S. are over $500 million, with double-digit growth. Around half of the coveted 25-to-34 age group (i.e. millennials) are kombucha drinkers. Yes, it’s popular now, but it also seems that kombucha is likely to be around for a while.


Bob Hutkins is the Food Doc. He is a professor at the University of Nebraska-Lincoln, where he teaches and conducts research in food science and food microbiology. Questions on any topic related to food, food safety, food ingredients and food processing can be sent to the Food Doc at

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2017 Annual Meeting Report Now Available

September 9, 2017. The 2017 Annual Meeting Report is now available. Read about the meeting including summaries from six discussion groups:
· How do we fully leverage the well-established and documented benefits of probiotics and prebiotics for the benefit of patients and the public
· Synbiotics –what are the advantages?
· Probiotic molecular mechanisms of action: where are we today?
· Identifying biomarkers linking the composition and function of the microbiome to health status.
· Diet-based disruptions of the microbiome: are they important and could probiotics and prebiotics modulate?
· New paradigms for translating probiotic and microbiome science into health-promoting products. Gregor Reid

bowl of yogurt with strawberries

Advice from a Nutritionist:  Eat More Fermented Foods.

September 2017. By Christopher Cifelli, PhD, VP of Nutrition Research, National Dairy Council.

Whenever I tell someone that I have a degree in nutrition science, I usually get asked, “Are carbs bad?” or “Should I avoid added sugars?” Rarely do I get asked “What should I be eating more of?” While vegetables, fruits, dairy and whole grains would all be perfectly suitable answers to that question, my go-to response is fermented foods.

Fermented foods have been around for thousands of years. Fermentation is the process of using specific microbes – for example, bacteria, yeast, and molds – to transform one food into another. For example, the fermentation process transforms milk into yogurt. Fermented foods are unique because they can contain live microbes, which can confer health benefits beyond simple nutrition. For instance, did you know that the microbes in fermented foods can help inhibit pathogen growth in the gut? Or, that eating certain fermented foods, such as yogurt, is associated with reduced chronic disease risk?

Government organizations across the globe provide dietary recommendations to help guide people choose the type of foods or diets that promote health. Commonalities include eating more fruits, vegetables, whole grains, beans, legumes and dairy. Another commonality – albeit a disconcerting one – is the lack of a recommendation for consuming fermented foods even though fermented foods, including red wine, kimchi, soya, and yogurt are key parts of healthy diet patterns.

Several recent publications have discussed the need to encourage the consumption of foods that can directly and beneficially impact our gut microbiota to improve overall health (e.g., Bell et al. or Gordon et al.). Identifying and consuming foods that can selectively impact the microbiota to benefit the host health should be a priority.

The time is now. Health professionals should review available evidence to determine how fermented foods fit into dietary recommendations to promote a healthy microbiota. They should encourage the public to increase their consumption of fermented foods to support the health of their microbiota and body. That way, the next time any of us are asked “What should I be eating” we can point to dietary recommendations and say — Fermented Foods!

Read more on fermented foods here and here.

Bacteria illustration

Suggestions for Making Safe Fermented Foods at Home

September 2017 – By Drs. Bruno Pot and Frédéric Leroy, Vrije Universiteit Brussels, Brussels, Belgium.

The impact of lifestyle on the composition and diversity of the human gut microbiota over the last five decades has been tremendous. This is thought to be mainly the result of a cumulative effect ascribed to the increased use of antibiotics and other drugs as well as dietary changes, including consuming less fermented foods that contain live microorganisms.

Fermented foods are important for a healthy diet, as they have the potential to improve the microbiota quality and diversity, are related with reduced disease risk, and can provide essential nutrients.  Consumers are constantly being informed about these benefits, leading to pleas for a return to home-made fermented foods. However, there is rarely mention of the risks that home-made natural fermentations can entail. While making fermented foods at home can be a good idea and help you consume more beneficial microbes, we should realize that the empirical knowhow, skills and equipment to make safe food fermentations may have disappeared over time. This blog is a gentle warning about the possible risks of non-controlled fermentations.

  • Use a starter culture: The use of specific starter cultures at sufficiently high concentration is recommended to properly initiate the fermentation of specific foods and to obtain sufficient control over the process. Relying on spontaneous fermentation (i.e., hoping that environmental bacteria or yeasts initiate the fermentation) increases the risk that uncontrolled fermentations by unsuitable bacteria, yeasts and molds will result in bad or variable quality. In the worst case, dangerous end-products will be obtained.
  • Twice is nice: Starters should not be used repeatedly. Because bacteria multiply several times per hour, their genetic material is changing continuously and the quality of the starter will change over time. It is therefore not a good idea to re-use your ‘old’ product to restart a ‘new’ fermentation all too often, although some fermented food ecosystems such as sourdough or water kefir may usually be ‘backslopped’ frequently. The risks are that off-flavours will be formed or that acidification, which protects your food against the growth of spoilage or pathogenic bacteria, will be too slow.
  • Choose wisely: Not all starters are necessarily safe, although commercially available ones should in principle have been checked for safety (See Helpful Information links below for guidance on findings the right starter). Some yeasts and lactic acid bacteria (LAB) can form compounds (for example, biogenic amines from amino acids) that can result in many health troubles like headache, blood pressure drops, diarrhoea, and even heart problems. You can avoid the production of biogenic amines by using selected starters that do not have the metabolic machinery to make them.
  • To breathe or not to breathe: Some fermentations, like the production of water kefir (usually using dried figs), should be performed in the absence of air and thus require a rubber sealing. For other fermentations, a complete submerging in brine or a covering with oil is necessary. Kombucha, on the contrary, needs a wide opening covered by a cloth that allows oxygen into the vessel. Uncontrolled anaerobic conditions can increase the risk for the growth of clostridia. In cheese making they can be the cause of cheese blowing up, in other conditions they may produce the deadly botulin toxin.
  • Avoid Moulds. Moulds are another problem linked to (too much) oxygen. Moulds can make mycotoxins which can make one very sick and any visible contamination should ring bells! It is not wise to scrape them off, as often they have produced toxins already, left spores or will remain present through their ‘roots’ which most of the time are not visible.
  • Hold the alcohol: During fermentation, sugars are converted to lactic and acetic acids, but also to ethanol. Therefore, the concentration of sugar added may impact the final alcohol levels of the end-product.
  • Pass the gas: In the case of water kefir, the use of a water lock can be necessary, as the CO2 gas which is formed during the fermentation may increase the pressure in the vessel, leading to potential breaking or surprises during opening. Therefore, blown fermented foods products should never be consumed.
  • Party crashers and acid balance: Not all bacteria are your friends. Some undesirables can be present on fresh vegetable products and can in themselves lead to spontaneous fermentation. Therefore, it is important to not let your fermentation be hijacked by these bacteria. The good bacteria should grow and produce acid quickly for a safe fermentation. Pathogens generally cannot grow in high acid environments (below pH 4 is a safe target). This acidity should be reached as quickly as possible during fermentation to avoid the growth of bacteria which can produce toxins or off flavours.
  • Nothing lasts forever: While high acid is essential, it does not protect the food indefinitely. Some yeasts and fungi can grow in high acid. As they grow, some can reduce acidity locally so that (mainly at the surface) other (potentially pathogenic) bacteria can develop
  • Use good quality raw materials. Use only good quality and fresh ingredients when deciding to ferment. While fermentation helps to preserve your fresh foods longer, it will not rescue (almost) spoiled products!
  • Summer and winter milk. If you use milk in your fermentation, it is also possible that the quality of the end product will be different along with the season, as summer milk, harvested from cows in the field, has a different composition from milk harvested from cows fed winterfeed.
  • Temperature. Temperature control is important. While for sauerkraut room temperature 18-22 (65-72°F) is fine, yoghurt fermentation is much better at 37°C (100°F). You, therefore, can expect differences in summer and winter if you do not control the temperature. Find the right spot in the house for both summer and winter.
  • Water activity. In addition to acidification, microbial control is often achieved by reduction of the water activity, generally by sufficient salting and/or drying. This is of major importance to produce fermented sausages. It is important to point out that raw meat is a particularly hazardous matrix, requiring even more care and attention when performed at home.
  • Salt and acetic acid (vinegar) concentration. Both ingredients help keep the pathogens at bay. Stick to recipes that have proven to be reliable.
  • Fermentation time. This is an important factor which can vary a lot and, in turn, impact the quality of your end product. Its critical nature is well known from wine making, in which the duration of the primary and secondary fermentation is well known to be crucial to the quality of the result. While in wine the primary fermentation usually takes between 3 to 7 days, the secondary fermentation can take much longer and will depend on the vial, the alcohol concentration and the yeast used. The fermentation of sauerkraut goes in three stages. ALL three are essential for a safe and tasteful product; a minimum of three to four weeks is necessary. Industrially produced yoghurt can be made in 8 hours, but at home it may take a few hours more. How much more again depends on the milk quality, the starter and the temperature.
  • Do’s and don’t’s: Do invest in a kitchen weighing scale and a thermometer that goes from 0 – 100 °C. Don’t even think about home-made sausage.  Don’t even think about raw-milk cheese.  Do start with simple foods like yogurt or kefir.  There are fool-proof kits for making beer (although they require some hardware).  Sauerkraut and kimchi are relatively easy to make.

Being aware of these simple concepts can help ensure the production of a healthy, tasty fermented food. Consumers should expect that the quality of the resulting fermented food will vary from lot to lot and they should be able to judge when a product is still safe for consumption and when it is not. Consumers should also be aware of the risk factors above and know how to select and handle equipment and execute procedures that will yield safe and nutritious end products.

For additional information:

Fermented Foods on the website.

Preparing Fermented Foods and Pickled Vegetables

The University of Georgia Cooperative Extension, the National Center for Home Food Preservation

Safe Preserving: Fermented Foods From the University of Wisconsin Extension

isapp consensus statement on prebiotics

Prebiotic definition updated by ISAPP

June 16, 2017. Prebiotic definition updated by ISAPP.

ISAPP published a consensus statement updating the prebiotic concept – Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics. Available open access from Nature Reviews in Gastroenterology and Hepatology, this paper offers a new definition of prebiotic: a substrate that is selectively utilized by host microorganisms conferring a health benefit. The consensus panel was led by Prof. Glenn Gibson, University of Reading, co-founder and past president of ISAPP. In 1995, Prof. Gibson, along with Professor Emeritus Marcel Roberfroid, first coined the term ‘prebiotic’. This new definition embraces progress in microbiome science and prebiotic innovation.

Publication of this consensus statement is just in time for the ISAPP 2017 annual meeting, which will be held June 27-29, 2017.

ISAPP’s previous consensus statement provided clarity on the definition and scope of the term ‘probiotic’. It remains the most highly downloaded paper published by Nature Reviews in Gastroenterology and Hepatology. It has been downloaded over 35,000 times.

ISAPP Annual Conference photos

ISAPP – Going beyond the science at our annual meetings.

June 2017. By Prof. Glenn Gibson, The University of Reading, UK.

Having never wrote a blog in my life (nor sent a twit nor Instamatic-gram nor facial networking book message), I had to consult my social media savvy children on what this blogging business was all about and who cares anyway. Both looked at me with exasperation, as if I had just crawled out of a cave, and gave me the highly informative answer “Write about what you want, you luddite, but try to make it less boring, than normal. If you write it, then it should perhaps be called clogging not blogging.”

What you might call a total vote of no confidence; anyway it did get me thinking. If this blog was for the ISAPP website, then surely it must have to at least mention probiotics and prebiotics – but that is what I have written about each day for as long as I can remember, and none of that ever had any impact! So, if you are reading this expecting to be educated on bugs, guts, health, faeces, etc, then please do move along to your next Google page.

When I think about what ISAPP has done differently, the science springs to mind, but then there has also been our annual meeting and the associated “fun” (for some people anyway….) activities that have been a hallmark. So, here is my reflection on these. This is all from my-  rapidly fading – memory and all mistakes are my own. I apologise if you have never attended ISAPP and hope that the below text does not discourage you from ever doing so!

It all began in London, Ontario in May 2002 with a treasure hunt in the woods and various ball games (remember, all delegates take part in these exercises). Bob Rastall eventually emerged as the winner and came out of the nearby woods clutching his hard earned treasure like it was a golden fleece. Actually it was a cuddly teddy bear – pink I think, to match his eyes. To this day, he still brags to students about the riches that can be gained with perseverance and unstinting application – as well as several pints of cold drink before tackling the task.

Next year, it was off to Henley UK for the epic Team Probiotics vs Team Prebiotics cricket match. Perhaps about 1% of participants fully understood the rules. Highlights included the Americans pitching the ball like a baseball (known as a beamer in cricketing parlance and highly illegal); Willem de Vos taking mobile phone calls while fielding at deep mid-wicket (which as you know is equidistant between deep square leg and cow corner but at the opposite side of the wicket to cover, point and extra cover i.e. 45o from mid on and fine leg); various attempts to catch the ball with one hand while clutching a full beer in the other; me being out for nothing (a duck) to the worse ever ball bowled in cricket history; the Americans (again) dropping the bat when running. As befitting a game that can last for 5 whole days, a draw was declared.

2004 saw us in the dizzy heights of Copper Mountain resort in Colorado. Here, the fun event took on added sophistication with a GPS driven game and various tasks to be completed. Have you ever seen over 100 highly trained scientists trying to master a small electronic gadget? (think Keystone Cops on amphetamines). Mary Ellen and family were the official adjudicators with Rick being introduced by her as “the nearest thing I’ll get to a secretary.” Gregor’s late night turn in the bar as a hybrid between Dave Lee Roth and one of the Supremes was not to be missed either.

On to Coleraine, Northern Ireland for a tour of the local attractions, including the spectacular Giants Causeway and Carrick-a-Rede rope bridge. Next, was London UK for an open meeting in 2007 where we were entertained by Jimmy Bright the professional comedian. He won over the notoriously tough scientific audience with his tales of British eccentricities and foibles – at least true for those who understood his accent.

The only venue to have hosted ISAPP twice is London, Ontario to where we returned in 2008. The social event here was a user friendly guide to social media by Amber MacArthur. Almost a decade later I write my first blog – well, these things do take time.

In 2009, we visited Newport Beach, California. Here, we hosted a joint meeting with NAS Sackler and therefore had to be on our best behaviour (for proof of this see the image). One highlight was seeing dolphins in the wild from Newport pier.

It was back to sporting excellence in 2010 at Castelldefel. Lots of Spanish family Sunday afternoons were completely ruined by the entire ISAPP descending on their beach for games, loudness and hilarity. This included football (Gregor acting as referee and goalscorer), volleyball, sand pictionary, quiz. Team Black Cats triumphed (had to mention that).

The next meeting was in Berkeley, I was not there so have no thoughts on the social prowess of the conference, but I did hear rumours of broken buses.

Cork in October 2012 featured a distillery trip and céad míle fáilt or póite (a hundred thousand hangovers). The next one in 2013, was joint with New York Academy of Sciences and featured one of the best views ever from a lecture hall. We also took time for a night boat trip on the Hudson.

Aberdeen was our location in 2014 for a joint meeting with the Rowett Institute of Nutrition and Health and INRA. Full scientific humiliation was evident at the Scottish Country Dancing event.

Georgetown, Washington had the ISAPP experience in 2015. This featured a once in a lifetime visit to the National Academy of Sciences for a posh dinner, and many contrived poses in the lecture auditorium.

Last year, we visited Turku, Finland and were transported back to the 1600’s for a medieval banquet hosted by Duke John and Princess Katherine, including the use of bread as a plate.

The 2017 meeting is almost upon us and we turn our mixture of science and fun towards Chicago. There is to be a bowling and beer event. Who knows what will happen, it won’t be pretty but it will definitely be competitive and, hopefully, memorable.

Goodness knows what new humiliation lies ahead for Singapore in 2018?

2017 Probiotic Product Guide

2017 Updated Clinical Guide for Probiotic Products Now Available

May 22, 2017. 2017 updates to the Clinical Guide for Probiotic Products are available. These helpful guides grade levels of evidence for commercial probiotic products in the United States and Canada.