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Archive Highlight: The role of microbes in gut-brain communication, with Prof. Emeran Mayer MD

 

Continuing our series on the microbiota-gut-brain axis, we are highlighting Episode 26 from our archives. In this episode, ISAPP podcast host Prof. Dan Tancredi PhD welcomes guest Prof. Emeran Mayer MD, a gastroenterologist and researcher at University of California Los Angeles. They talk about the microbiota-gut-brain axis, covering its evolutionary origins and how this complex system works in the human body to support overall health.

Key topics from this episode:

  • Microbiota-gut-brain communication has a long evolutionary history: microbes have been around for billions of years and they stored a lot of information in their genes. At some point in evolution microbes got inside the digestive tube of a primitive marine animal called hydra and it proved advantageous for this animal.
  • The hydra shows the origin of the human enteric nervous system (ENS): microbes live inside this tube and transfer genes to the nerve cells of this digestive tube, showing the origin of neurotransmitters.
  • Today in humans the neurotransmitters influence gene expression of microbes and change the microbial behaviors; the metabolites produced feed back to the brain.
  • Prof. Mayer’s initial interest as a gastroenterologist was the ENS and how it regulates motility. Subsequently the ENS was found to regulate many gut functions. The gut also houses a large part of the immune system and a complex hormonal system, and all these systems are connected with each other and communicate with the brain.
  • There is an increasing understanding that many chronic diseases relate to Inappropriate engagement of the immune system, starting in the gut.
  • When Prof. Mayer started in the field, the term “gut health” did not exist. Now it’s a ubiquitous term which has associations with wellbeing, acknowledging the gut has influence on many other body systems.
  • The associations between gut (microbiota) and brain health started with provocative animal experiments from Cork, Ireland, in which researchers manipulated the gut microbiome and found changes in emotion-like behaviors of animals. However, it has been difficult to translate to human interventions.
  • How do microbiome-targeted dietary interventions affect the brain? We do know the “Standard American Diet” (deficient in fiber) has changed the gut microbes in a way that compromises the production and maintenance of the gut barrier. 
  • There are many misconceptions about “leaky gut”, but basically contact between beneficial microbes and immune system sensors stimulate the immune system of the gut to low-grade inflammation. This can alter the tight junctions, making the gut more permeable, and ultimately this can affect the brain. Diet can affect the role of microbes in maintaining an effective gut barrier.
  • Prof. Mayer describes how he ended up studying the microbiota-gut-brain axis – he would not have predicted how important and popular this field would become.
  • In the future, there will be more sophisticated and personalized interventions. He sees a paradigm shift happening from reductionist approaches in medicine to systems biological approaches. This field is making us acknowledge that diet will play a major role.

Episode links:

About Prof. Emeran Mayer MD:

Emeran A Mayer is a Gastroenterologist, Neuroscientist and Distinguished Research Professor in the Department of Medicine at the David Geffen School of Medicine at UCLA, the Executive Director of the G. Oppenheimer Center for Neurobiology of Stress & Resilience and Founding Director of the Goodman Luskin Microbiome Center at UCLA. He is one of the pioneers and leading researchers in the bidirectional communication within the brain gut microbiome system with wide-ranging applications in intestinal and brain disorders. He has published 415 scientific papers, co edited 3 books and has an h-index of 125. He published the best selling books The Mind Gut Connection in 2016, the Gut Immune Connection in June 2021, and the recipe book Interconnected Plates in 2023. He is currently working on a MasterClass and a PBS documentary about the mind gut immune connection. He is the recipient of numerous awards, including the 2016 David McLean award from the American Psychosomatic Society and the 2017 Ismar Boas Medal from the German Society of Gastroenterology and Metabolic Disease.

Archive Highlight: Biotics in animal and human nutrition, with Prof. Kelly Swanson PhD

 

Completing our series on the role of biotics in animal health, we are highlighting Episode 22 from our archives. In this episode, Prof. Kelly Swanson PhD from University of Illinois at Urbana-Champaign discusses the role of biotics in animal and human nutrition. He reviews the criteria for prebiotics and synbiotics, then discusses how we gain knowledge about nutrition and the role of biotics in animals compared to humans.

Key topics from this episode:

  • A good argument can be made that biotics are essential for our diet; they are beneficial even if efficacy is sometimes difficult to prove.
  • Nutrients have an impact on the host’s health and simultaneously on the host-associated microbes.
  • Health benefits are essential to the FDA definition of fiber.
  • Antibiotics’ effect on the microbiota: short-term effects may be minor, but we still don’t know the long-term effects.
  • The synbiotics definition, criteria for products to meet this definition, and the health outcomes from using these biotic substances.
  • The difference between complementary and synergistic synbiotics.
  • When studying biotics in companion animals (cats and dogs), can results from one host be extrapolated to another host? Final studies should be in the target host.
  • Biotics are important in veterinary medicine and a popular topic of study.
  • Predictions about the future of nutrition science as informed by the microbiome.

Episode links:

Additional resources:

About Prof. Kelly Swanson:

Kelly Swanson is the Kraft Heinz Company Endowed Professor in Human Nutrition at the University of Illinois at Urbana-Champaign. His laboratory studies the effects of nutritional interventions, identifying how diet impacts host physiology and gut microbiota. His lab’s primary emphasis is on gastrointestinal health and obesity in dogs, cats, and humans. Much of his work has focused on dietary fibers and ‘biotics’. Kelly has trained over 40 graduate students and postdocs, published over 235 peer-reviewed manuscripts, and given over 150 invited lectures at scientific conferences. He is an active instructor, teaching 3-4 nutrition courses annually, and has been named to the university’s ‘List of Teachers Ranked as Excellent by Their Students’ 30 times. He serves on advisory boards for many companies in the human and pet food industries and non-profit organizations, including the Institute for the Advancement of Food and Nutrition Sciences and International Scientific Association for Probiotics and Prebiotics.

2023 in Review: Highlights in the Field of Biotic Science

By Kristina Campbell, Prof. Colin Hill PhD, Prof. Sarah Lebeer PhD, Prof. Maria Marco PhD, Prof. Dan Merenstein MD, Prof. Hania Szajewska MD PhD, Prof. Dan Tancredi PhD, Prof. Kristin Verbeke PhD, Dr. Gabriel Vinderola PhD, Dr. Anisha Wijeyesekera PhD, and Marla Cunningham

Biotic science is an active field, with over 6,600 scientific papers published in the past year. The scientific work that emerged in 2023 covered many diverse areas – from probiotic mechanisms of action to the use of biotics in clinical populations. In parallel with the scientific advancements, consumer interest in gut health and biotics is at an all-time high. A recent survey showed that 67 percent of consumers are familiar with the concept of probiotics and 51 percent of those who consume probiotics do so with the aim of supporting gut health.

Several ISAPP-affiliated experts took the time to reflect on 2023 and identify the most important directions in the fields of probiotics, prebiotics, synbiotics, postbiotics, and fermented foods. Below are these experts’ picks for the top developments in biotic science and application during the past year.

Increased recognition of biotics as a category

After ISAPP’s publication of the recent synbiotics and postbiotics definitions in 2020-2021, board members and others began referring to probiotics, prebiotics, synbiotics, and postbiotics collectively as “biotics”. 2023 has seen the term being used more widely (for example, in article headlines and communications from major organizations) to refer to these substances as a broad group.

Steps forward and steps back in the regulation of live microbial interventions

The actions of regulators have a profound impact on how biotic science is applied and how products can reach consumers. On the positive side, 2023 heralded the regulatory approval of two live microbial drug products for recurrent C. difficile infection by the US Food and Drug Administration (FDA). Both products are derived from fecal samples, but one is delivered to the patient gastrointestinal (GI) tract by enema, and the other is delivered orally.

Meanwhile, a case of fatal bacteremia in a preterm infant who had been given a probiotic product prompted the FDA to issue a warning letter to healthcare practitioners about probiotics in preterm infants, as well as warning letters to two probiotic manufacturers. These actions had the concerning effect of reducing access to probiotics for this population, despite the accumulated evidence that probiotics effectively prevent necrotizing enterocolitis in preterm infants. As outlined in ISAPP’s scientific statement on the FDA’s actions, the regulatory decision weighting the risks of commission over omission did not reflect the wealth of evidence for probiotic efficacy in this population and the low risk of harm.

Wider awareness of the postbiotic concept and definition

Scientific discussions on postbiotics continued throughout 2023, with several debates and conference sessions devoted to discussion of the postbiotic concept – including the status of metabolites in the definition. According to ISAPP board member Dr. Gabriel Vinderola PhD, who was a co-author on the definition paper and an active participant in many of these debates, the ISAPP definition is gaining traction and the debates have been useful in pinpointing further areas of clarification for the sake of regulators and other stakeholders. As shared with the audience at Probiota Americas 2023 in Chicago, Health Canada became the first regulatory agency to address the definition, and has started considering the term postbiotics under the ISAPP definition.

Advances in technologies for analyzing different sites in the digestive tract

When studying how biotics interface with the host via the gut microbiota, the science has relied mainly on analysis of fecal samples, with the majority of the GI tract remaining a ‘black box’. But a 2023 paper by Shalon et al., which was discussed at the ISAPP meeting in Denver, describes a device able to collect intestinal samples from different regions in the GI tract. Analysis of the metabolites and microbes indicated clear regional differences, as well as marked differences between samples in the GI tract versus fecal samples (for example, with respect to bile acids); an accompanying paper revealed novel insights into diet and microbially-derived metabolites. Efforts are underway across the world to develop smart pills or robotic pills that take samples all along the GI tract. Some devices have sensors that immediately signal to a receiver and others have been engineered to release therapeutic contents. Although these technologies may need more validation before they are useful in research or clinical contexts, they may greatly expand knowledge of the intestinal microbial community and how it interacts with biotic substances.

First convincing evidence linking intake of live microbes with health benefits

When an ISAPP discussion group in 2019 delved into the question of whether a higher intake of safe, uncharacterized live microbes had the potential to confer health benefits, it spurred a program of scientific work to follow. Efforts of this group in subsequent years led to the publication of an important study in 2023: Positive Health Outcomes Associated with Live Microbe Intake from Foods, Including Fermented Foods, Assessed using the NHANES Database. Researchers analyzed data from a large US dietary database and found clear but modest health benefits associated with consuming higher levels of microbes in the daily diet.

The benefits of live dietary microbes are being explored further in the scientific literature (for example, here, here, and here) and are likely to remain an exciting topic of study in the years ahead, building evidence globally for the health benefits of consuming a higher quantity of live microbes.

Increased interest in candidate prebiotics

Polyphenols have long been studied for their health benefits, but newer evidence suggests they may have prebiotic effects, achieving their health benefits (in part) through interactions with the gut microbiota. A theme at conferences and in the scientific literature has been the use of polyphenols to modulate the gut microbiota for specific health benefits. More than a dozen reviews on this topic were published in 2023, and several of them focused on how polyphenols may achieve health benefits in very specific conditions, such as diabetes or inflammatory bowel disease.

Another substrate receiving much attention for its prebiotic potential are human milk oligosaccharides (HMOs). HMOs, found in human milk, support a nursing infant’s health by encouraging the growth of beneficial gut microbes. Several articles in 2023 have delved into the mechanisms of HMO metabolism by the gut microbiota, and explored its potential as a dietary intervention strategy to improve gut health in adults.

Sharper focus on evidence for the health and sustainability benefits of fermented foods

Fermented foods are popular among consumers, despite only early scientific knowledge on whether and how they might confer health benefits (see ‘First convincing evidence linking intake of live microbes with health benefits’, above). ISAPP board member Prof. Maria Marco PhD co-authored a review led by Dr. Paul Cotter PhD in Nature Reviews Gastroenterology and Hepatology on the GI-related health benefits of fermented foods. The paper clearly lays out the potential mechanisms under investigation and identifies gaps to be addressed in the ongoing study of fermented foods.

As calls for reducing carbon footprints continue across the globe, plant-based fermented foods are being singled out as an area for innovation and expansion. One example of how these foods are being explored is through the HealthFerm project, a 4-year, 13.1 million Euro project involving 23 partners from 10 countries, which is focused on understanding how to achieve more sustainable, healthy diets by leveraging fermented foods and technologies.

Novel findings related to lactic acid bacteria

Lactic acid bacteria (LAB) are some of the most frequently-studied microbial groups, but scientists have only begun to uncover the workings of this diverse group of bacteria and how they affect a variety of hosts. These bacteria are used as probiotics and are often beneficial members of human and animal microbiomes, and they are also essential to making fermented foods. This year marked the first ever Gordon Research Conference on LAB in California, USA. Attendees showcased the diversity of research on lactic acid bacteria, and the meeting was energized by the early investigators present and by the interest in LAB in other disciplines including medicine, ecology, synthetic biology, and engineering. One example of a scientific development in this area was the further elucidation of the mechanism of Lactiplantibacillus plantarum’s extracellular electron transfer.

Progress on the benefits and mechanisms of action for probiotics to improve the effectiveness of cancer immunotherapies

Researchers have known for several years that the gut microbiota can be a determinant of the efficacy of cancer immunotherapy drugs that involve immune checkpoint blockade, but interventions that target the gut microbiota to improve response to immunotherapies have been slower to develop. This year saw encouraging progress in this important area, with probiotic benefits and mechanisms of action being demonstrated in several papers. Two of the most highly cited probiotics papers of the year centered on this topic: one showing how a tryptophan metabolite released by Limosilactobacillus reuteri (formerly Lactobacillus reuteri — see this ISAPP infographic) improves immune checkpoint inhibitor efficacy, and another paper that reviewed how gut microbiota regulates immunity in general, and immune therapies in particular.

Updated resource available on probiotics and prebiotics in gastroenterology

This year the World Gastroenterology Organisation (WGO) guidelines on probiotics and prebiotics were updated to reflect the latest evidence, with contributions from ISAPP board member Prof. Hania Szajewska MD PhD and former board member Prof. Francisco Guarner MD PhD. The guideline lists indications for probiotic and prebiotic use, and how the use of these substances may differ in pediatric versus adult populations. Find the guideline here.

Episode 28: Lactobacilli in the microbiomes of the gut, skin, reproductive tract and more

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

Lactobacilli in the microbiomes of the gut, skin, reproductive tract and more, with Prof. Kingsley Anukam PhD

Episode summary:

In this episode, the ISAPP podcast hosts cover a range of topics related to lactobacilli and health with Prof. Kingsley Anukam PhD from Nnamdi Azikiwe University in Nigeria. Prof. Anukam has a special interest in lactobacilli, and studies lactobacilli in microbiomes across many different contexts: fermented foods, skin, gut, and reproductive tract sites. He talks about the wide range of research he has led in Nigeria using diverse sources of funding.

Key topics from this episode:

  • Prof. Anukam describes his collaboration with Prof. Gregor Reid PhD early in his career, prompted by a paper claiming that African women did not have vaginal microbiomes dominated by lactobacilli. Subsequent work showed this was not the case – confounding factors contributed to the initial result.
  • He cautions researchers against making conclusions about race or ethnicity when geographical variations or other factors could better account for the differences between groups. In studies it’s important to specify the geography as well as the other factors (dietary, cultural) that may impact the gut microbiome in these populations.
  • There is a long history of fermented foods in Africa but not a lot of research has been done on them. In a 2009 paper with Prof. Reid, Prof. Anukam reported isolated lactic acid species from a fermented food called okpeye produced in Eastern Nigeria. The isolates showed potential for industrial applications.
  • Most of his research studies are funded from outside Nigeria, with different sources of funding.
  • ‘Parachute’ science is common in Africa, where researchers come into an African country, obtain samples and leave. He encourages researchers to involve local scientists to build capacity and allow them to do the analysis.
  • Prof. Anukam describes a clinical trial he led on the skin microbiome and malodor in Nigerian youth. He found the skin microbiome in the armpit was altered if individuals used deodorants and antiperspirants; and these individuals kept having the same malodor issues. Individuals with less odor were found to have more lactobacilli on the skin, with differences in composition between men and women. They developed a topical cream to use as an intervention for 14 days, and found that lactobacilli on the skin increased and less odor was reported.
  • The microbiome(s) of the male reproductive organs have not been studied very much. Semen has a microbiome, and this is shown by both culture and non-culture methods. It is dominated by lactobacilli, and this corresponds with semen quality. The evidence is mixed on the existence of testes and prostate microbiomes. A gut-testes connection may exist, however, as shown in mouse studies.
  • Prof. Anukam says in a study of subjects seeking reproductive healthcare, different microbiomes were observed both in males and females having difficulty conceiving.
  • The semen microbiome could play a significant role in reproduction – for example, it may produce metabolites that could affect the female reproductive tract and influence the environment for conception to take place. When doing in vitro fertilization, evidence has shown that if the samples are contaminated by pathogens, it can be difficult to achieve conception.

Episode links:

About Prof. Kingsley Anukam PhD:

Kingsley C Anukam is a research scientist in human microbiome and biotherapeutics with over 20 years experience. He shares his time between Canada and Nigeria as an adjunct professor at Nnamdi Azikiwe University where he assists in the training and supervision of post graduate students working in the area of probiotics, fermented foods, human microbiome, infectious diseases, laboratory diagnostics, human genomics and forensic DNA analysis. He had his graduate education in Nigeria and post doctorate training in Dr. Gregor Reid’s Lab at Lawson Health Research Institute and Department of Microbiology and Immunology, Western University, Canada. He is the first from Africa to show that vaginal microbiome of healthy Nigerian women is similar to women from other populations irrespective of geographical location. He has sequenced and annotated the full genome of over 10 Lactobacillus species of African origin mainly from the reproductive tract and African fermented foods in collaboration with Prof. Sarah Lebeer. He played a significant role in the formation of the DORA project, an ISALA-inspired citizen science for vaginal health in Nigeria. He has over 80 scientific research publications in peer-reviewed journals and listed among first 10 most cited researcher at Nnamdi Azikiwe University by Google Scholar. He is currently the Chief Editor, Journal of Medical Laboratory Science, and a peer-reviewer of several international journals.

Inaugural nominations open for ISAPP Award: The Sanders Award for Advancing Biotic Science

With this year’s retirement of ISAPP’s longtime Executive Science Officer, Dr. Mary Ellen Sanders PhD, the ISAPP board of directors sought a suitable way to honor her contributions in advancing scientific development in the fields of probiotics, prebiotics, synbiotics, postbiotics and fermented foods. Many scientists in these fields have commended Mary Ellen’s leadership, initiative, collaboration, and communication over the last 20 years.

Board members decided to launch a new award in Mary Ellen’s honor: The Sanders Award for Advancing Biotic Science. This award aims to promote excellence in the biotic field and recognize exceptional achievement across a range of potential endeavours including research, scientific communication and stakeholder engagement. A cash grant and travel to the ISAPP meeting will be awarded to the annual recipient starting in 2024.

Prof. Gregor Reid PhD, ISAPP co-founder and former board member, who championed the award, says: “What better way to applaud leadership and someone who has placed honesty, stewardship and evidence-based progress above all else, than to have an annual celebration of advancement in these critically important fields.”

The ISAPP board invited members of the ISAPP community to donate to a special endowment fund in order to sustain the Sanders Award over the long term, and this fund received over $34,000 of donations.

ISAPP President, Prof. Dan Merenstein MD, says: “We have really appreciated and been touched by the generous individual and company donations. But none of that is surprising because Mary Ellen has been a positive force in this field since the beginning and everyone who works with her respects and enjoys working with her.”

The award was launched in August, 2023 and nominations are open through to November, 2023.

Find out more about the award here.

Episode 27: Investigating the benefits of live dietary microbes

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

Investigating the benefits of live dietary microbes, with Prof. Colin Hill PhD and Prof. Dan Tancredi PhD

Episode summary:

In this episode, the ISAPP podcast hosts themselves are the experts: Prof. Colin Hill PhD from APC Microbiome Ireland / University College Cork and Prof. Dan Tancredi PhD from University of California – Davis talk about their recent work investigating the health benefits from consuming higher quantities of live dietary microbes – and not just microbes that meet the probiotic criteria.

Key topics from this episode:

  • Profs. Hill and Tancredi were involved with others in a recent series investigations & 3 published papers on whether there should be a recommended daily intake of live microbes.
  • Prof. Hill started by writing a blog, prompted by the finding that meta-analyses on probiotics tended to show some general benefits for health. Would this apply to any safe, live microbes – even those that do not meet the probiotic criteria?
  • Various hypotheses (hygiene hypothesis, old friends hypothesis, missing microbes hypothesis) posit that a lack of microbes is associated with poorer health.
  • Clean water and clean food have reduced the burden of infectious disease. But at the same time, across populations there has been an increase in chronic diseases. Could a lack of live dietary microbes be contributing to this increase in chronic disease, because the immune system lacks adequate inputs? Or in other words, could there be a general health benefit for healthy people in consuming high quantities of live microbes?
  • To address the hypothesis scientifically: they investigated the health status of people who eat large vs. small numbers of safe live microbes in their diets. Starting with NHANES data in the US, the researchers classified foods into categories of high / medium / low numbers of live microbes.
  • Note that not all fermented foods contain live microbes, but some contain high numbers of live microbes. A possible confounding factor in the analysis was that high microbe foods tend to be healthier foods.
  • The researchers published a series of 3 papers. The 3rd paper showed an association between intake of live microbes and various (positive) measurements of health. Consistent, modest improvements were seen across a range of health outcomes.
  • This is an association, but statistically the team did use regression analysis to statistically adjust for effects on health that could be due to other factors besides the live microbial intake.
  • The take-home is not to eat unsafe or rotten food, but rather to eat more high-microbe or fermented foods, and in general eat a healthy diet.

Episode links:

Additional Resources:

Live Dietary Microbes: A role in human health. ISAPP infographic.

About Prof. Colin Hill PhD:
Colin Hill has a Ph.D in molecular microbiology and is a Professor in the School of Microbiology at University College Cork, Ireland. He is also a founding Principal Investigator in APC Microbiome Ireland, a large research centre devoted to the study of the role of the gut microbiota in health and disease. His main interests lie in the role of the microbiome in human and animal health. He is particularly interested in the effects of probiotics, bacteriocins, and bacteriophage. In 2005 Prof. Hill was awarded a D.Sc by the National University of Ireland in recognition of his contributions to research. In 2009 he was elected to the Royal Irish Academy and in 2010 he received the Metchnikoff Prize in Microbiology and was elected to the American Academy of Microbiology. He has published more than 600 papers and holds 25 patents. More than 80 PhD students have been trained in his laboratory. He was president of ISAPP from 2012-2015.

About Prof. Dan Tancredi PhD:
Daniel J. Tancredi, PhD, is Professor in Residence of Pediatrics in the University of California, Davis School of Medicine. He has over 25 years of experience and over 300 peer-reviewed publications as a statistician collaborating on a variety of health-related research. A frequent collaborator on probiotic and prebiotic research, he has attended all but one ISAPP annual meeting since 2009 as an invited expert. In 2020, he joined the ISAPP Board of Directors. Colin Hill and Daniel co-host the ISAPP Podcast Series “Science, Microbes, and Health”. On research teams, he develops and helps implement effective study designs and statistical analysis plans, especially in settings with clusters of longitudinal or otherwise correlated measurements, including cluster-randomized trials, surveys that use complex probability sampling techniques, and epidemiological research. He teaches statistics and critical appraisal of evidence to resident physicians; graduate students in biostatistics, epidemiology, and nursing; and professional scientists. Dan grew up in the American Midwest, in Kansas City, Missouri, and holds a bachelor’s degree in behavioral science from the University of Chicago and masters and doctoral degrees in mathematics from the University of Illinois at Chicago. He lives in the small Northern California city of Davis, with his wife Laurel Beckett (UC Davis Distinguished Professor Emerita), their Samoyed dogs Simka and Milka, and near their two grandkids.

Episode 26: The role of microbes in gut-brain communication

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

The role of microbes in gut-brain communication, with Prof. Emeran Mayer MD

Episode summary:

In this episode, ISAPP podcast host Prof. Dan Tancredi PhD welcomes guest Prof. Emeran Mayer MD, a gastroenterologist and researcher at University of California Los Angeles. They talk about the microbiota-gut-brain axis, covering its evolutionary origins and how this complex system works in the human body to support overall health.

Key topics from this episode:

  • Microbiota-gut-brain communication has a long evolutionary history: microbes have been around for billions of years and they stored a lot of information in their genes. At some point in evolution microbes got inside the digestive tube of a primitive marine animal called hydra and it proved advantageous for this animal.
  • The hydra shows the origin of the human enteric nervous system (ENS): microbes live inside this tube and transfer genes to the nerve cells of this digestive tube, showing the origin of neurotransmitters.
  • Today in humans the neurotransmitters influence gene expression of microbes and change the microbial behaviors; the metabolites produced feed back to the brain.
  • Prof. Mayer’s initial interest as a gastroenterologist was the ENS and how it regulates motility. Subsequently the ENS was found to regulate many gut functions. The gut also houses a large part of the immune system and a complex hormonal system, and all these systems are connected with each other and communicate with the brain.
  • There is an increasing understanding that many chronic diseases relate to Inappropriate engagement of the immune system, starting in the gut.
  • When Prof. Mayer started in the field, the term “gut health” did not exist. Now it’s a ubiquitous term which has associations with wellbeing, acknowledging the gut has influence on many other body systems.
  • The associations between gut (microbiota) and brain health started with provocative animal experiments from Cork, Ireland, in which researchers manipulated the gut microbiome and found changes in emotion-like behaviors of animals. However, it has been difficult to translate to human interventions.
  • How do microbiome-targeted dietary interventions affect the brain? We do know the “Standard American Diet” (deficient in fiber) has changed the gut microbes in a way that compromises the production and maintenance of the gut barrier. 
  • There are many misconceptions about “leaky gut”, but basically contact between beneficial microbes and immune system sensors stimulate the immune system of the gut to low-grade inflammation. This can alter the tight junctions, making the gut more permeable, and ultimately this can affect the brain. Diet can affect the role of microbes in maintaining an effective gut barrier.
  • Prof. Mayer describes how he ended up studying the microbiota-gut-brain axis – he would not have predicted how important and popular this field would become.
  • In the future, there will be more sophisticated and personalized interventions. He sees a paradigm shift happening from reductionist approaches in medicine to systems biological approaches. This field is making us acknowledge that diet will play a major role.

Episode links:

About Prof. Emeran Mayer MD:

Emeran A Mayer is a Gastroenterologist, Neuroscientist and Distinguished Research Professor in the Department of Medicine at the David Geffen School of Medicine at UCLA, the Executive Director of the G. Oppenheimer Center for Neurobiology of Stress & Resilience and Founding Director of the Goodman Luskin Microbiome Center at UCLA. He is one of the pioneers and leading researchers in the bidirectional communication within the brain gut microbiome system with wide-ranging applications in intestinal and brain disorders. He has published 415 scientific papers, co edited 3 books and has an h-index of 125. He published the best selling books The Mind Gut Connection in 2016, the Gut Immune Connection in June 2021, and the recipe book Interconnected Plates in 2023. He is currently working on a MasterClass and a PBS documentary about the mind gut immune connection. He is the recipient of numerous awards, including the 2016 David McLean award from the American Psychosomatic Society and the 2017 Ismar Boas Medal from the German Society of Gastroenterology and Metabolic Disease.

Episode 25: The effects of metabolites in the colon

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

The effects of metabolites in the colon, with Prof. Kristin Verbeke PhD

Episode summary:

In this episode, the ISAPP podcast hosts talk about colonic metabolites with Prof. Kristin Verbeke PhD, from KU Leuven, Belgium. She talks about characterizing microbial metabolism in the colon and the consequences of producing various metabolites, both beneficial ones (such as short-chain fatty acids) and potentially detrimental ones.

Key topics from this episode:

  • Prof. Verbeke is a pharmacist by training, and now leads hospital breath testing and carries out research on microbial metabolites in the gastrointestinal tract, including how prebiotics and probiotics can change bacterial metabolism.
  • The majority of protein in the diet is digested in the small intestine, but about 5% of animal protein and 10-15% of plant protein reaches the large intestine to be fermented by the microbiota. This produces metabolites, which are shown in vitro to be toxic. However, in vivo there is less evidence of toxicity; the negative effects of these metabolites may be reduced by the interactions of different compounds in the colon.
  • Short-chain fatty acids (SCFAs) are produced when the body digests dietary fiber, and Prof. Verbeke’s group and others are investigating whether they are responsible for the benefits of eating fiber.
  • Most SCFAs are quickly absorbed in the large intestine, and they serve as an energy source for the cells. They then travel to the liver via portal circulation, where they have additional functions. What’s left over reaches systemic circulation.
  • The difficulty is knowing how many SCFAs are produced in the colon, and how many reach systemic circulation. In one experiment, they labeled the SCFAs that were administered to the colon via capsule; 36% ended up in systemic circulation. Further, when SCFAs were administered at physiological doses the subjects receiving them (compared to placebo) showed a lower cortisol response to stress.
  • SCFAs also affect fat oxidation and fat synthesis in the liver. Their relevance to non-alcoholic fatty liver disease are being investigated.
  • It’s important to eat fiber, and lots of different types. After fiber consumption, SCFAs increase in a sustained manner and take about 8h to get back to baseline. But with SCFA delivery via capsule they spike quickly and then disappear.
  • As for coatings to deliver to the colon, some coatings are time-dependent, pH dependent, etc. and this is an area for further exploration.

Episode links:

About Prof. Kristin Verbeke PhD:

Kristin Verbeke graduated from the KU Leuven, Belgium as a pharmacist in 1991. She obtained a PhD in Pharmaceutical Sciences at the Laboratory of Radiopharmaceutical Chemistry in 1995 and subsequently spend a postdoctoral period in developing radioactively labelled compounds. In 2002, she was appointed at the department of gastroenterology of the Medical Faculty of the Leuven University where she got involved in the use of stable isotope labelled compounds to evaluate gastrointestinal functions. Within the University Hospitals Leuven, she is responsible for the clinical application of diagnostic 13C- and H2-breath tests. Her current research interest specifically addresses the microbial bacterial metabolism in the human colon. Her team has developed several analytical techniques based on mass spectrometry and stable isotope or radioisotope technologies to evaluate several aspects of intestinal metabolism and function in humans (transit time, intestinal permeability, carbohydrate fermentation, protein fermentation, metabolome analysis). Collaborative research has allowed showing an aberrant bacterial metabolism in patient groups with end stage renal failure, inflammatory bowel diseases, irritable bowel disorders and alcohol abuse. These collaborations all have resulted in high quality peer-reviewed papers. In addition, she showed the impact of dietary interventions (modulation of macronutrient composition, pre- or probiotic interventions) on the microbial metabolism and its impact on health. As a PI, she acquired grant support from the university and different funding bodies and successfully completed these projects. Similarly, she supervised several PhD projects that all resulted in the achievement of a PhD degree. Her research resulted in over 200 full research papers. Together with colleague Prof. J. Delcour, she was the beneficiary of the W.K. Kellogg Chair in Cereal Sciences and Nutrition (2010-2020). She is the president of the Belgian Nutrition Society, the vice-chair of the Leuven Food Science and Nutrition Center, and the co-chair of the Prebiotic task force at ILSI Europe. Furthermore, Kristin Verbeke is the editor of the journal Gut Microbiome and member of the editorial board of Gastrointestinal Disorders. Kristin joined the ISAPP Board of Directors in 2023.

Episode 24: Reflections on the probiotic field and ISAPP’s role

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

Reflections on the probiotic field and ISAPP’s role, with Dr. Mary Ellen Sanders PhD

Episode summary:

In this episode, the ISAPP podcast hosts talk about how the probiotic field has evolved over the past 20 years with Dr. Mary Ellen Sanders PhD, ISAPP’s outgoing executive director. She describes how ISAPP is a unique organization advancing the science in the field, highlights what she has enjoyed about being a part of the ISAPP community, and looks ahead to the future of the field.

Key topics from this episode:

  • Sanders describes her career path and how it led to her role with ISAPP. 
  • Both ISAPP and Sanders’ role have changed over time, but she always appreciated two things: great scientific discussions, and interacting with an excellent board of directors.
  • ISAPP has always been dedicated to following the science, highlighting where the evidence is but also the shortcomings of the evidence.
  • The development of microbiome science changed the field of probiotics but it remains important to focus on what probiotics can do for health, rather than what they can do for the microbiome.
  • Mechanisms are important to elucidate, but the most important thing is whether a product impacts health.
  • Sanders says regulations are needed and in the future she hopes regulators will reach out to the expert scientists more frequently and be clear about the standards they expect for a claim.
  • ISAPP meetings are unique–both scientifically enlightening and a lot of fun. Longtime ISAPP board member Gregor Reid had the initial idea for the successful ‘discussion groups’ held every year. 
  • In the future, Sanders thinks probiotics will be used more precisely, like medicines. But also the concept of live dietary microbes may become more popular, with quantities of safe microorganisms being consumed for health benefits.

Episode links:

About Dr. Mary Ellen Sanders PhD:

Mary Ellen Sanders, PhD has served in several roles within ISAPP. She was the founding president, executive science officer and executive director and has retired from ISAPP as of June 30, 2023. She is also a consultant in the area of probiotic microbiology. She works internationally with food and supplement companies to develop new probiotic products and offers perspective on paths to scientific substantiation of probiotic product label claims. She is the current chair of the United States Pharmacopeia’s Probiotics Expert Panel, was a member of the working group convened by the FAO/WHO that developed guidelines for probiotics and serves on the World Gastroenterology Organisation Guidelines Committee preparing practice guidelines for the use of probiotics and prebiotics for gastroenterologists.

Biotics in animal and human nutrition

Episode 22: Biotics in animal and human nutrition

Biotics in animal and human nutrition

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

Biotics in animal and human nutrition, with Prof. Kelly Swanson

Episode summary:

In this episode, the ISAPP podcast hosts join guest Prof. Kelly Swanson PhD from University of Illinois at Urbana-Champaign, to discuss the role of biotics in animal and human nutrition. They review the criteria for prebiotics and synbiotics, then discuss how we gain knowledge about nutrition and the role of biotics in animals compared to humans.

Key topics from this episode:

  • A good argument can be made that biotics are essential for our diet; they are beneficial even if efficacy is sometimes difficult to prove.
  • Nutrients have an impact on the host’s health and simultaneously on the host-associated microbes.
  • Health benefits are essential to the FDA definition of fiber.
  • Antibiotics’ effect on the microbiota: short-term effects may be minor, but we still don’t know the long-term effects.
  • The synbiotics definition, criteria for products to meet this definition, and the health outcomes from using these biotic substances.
  • The difference between complementary and synergistic synbiotics.
  • When studying biotics in companion animals (cats and dogs), can results from one host be extrapolated to another host? Final studies should be in the target host.
  • Biotics are important in veterinary medicine and a popular topic of study.
  • Predictions about the future of nutrition science as informed by the microbiome.

Episode links:

Additional resources:

About Prof. Kelly Swanson:

Kelly Swanson is the Kraft Heinz Company Endowed Professor in Human Nutrition at the University of Illinois at Urbana-Champaign. His laboratory studies the effects of nutritional interventions, identifying how diet impacts host physiology and gut microbiota. His lab’s primary emphasis is on gastrointestinal health and obesity in dogs, cats, and humans. Much of his work has focused on dietary fibers and ‘biotics’. Kelly has trained over 40 graduate students and postdocs, published over 235 peer-reviewed manuscripts, and given over 150 invited lectures at scientific conferences. He is an active instructor, teaching 3-4 nutrition courses annually, and has been named to the university’s ‘List of Teachers Ranked as Excellent by Their Students’ 30 times. He serves on advisory boards for many companies in the human and pet food industries and non-profit organizations, including the Institute for the Advancement of Food and Nutrition Sciences and International Scientific Association for Probiotics and Prebiotics.

Genetically modified microorganisms for health

Episode 21: Genetically modified microorganisms for health

Genetically modified microorganisms for health

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

Genetically modified microorganisms for health, with Dr. Carlos Gómez-Gallego

Episode summary:

In this episode, ISAPP podcast host Dan Tancredi joins guest Carlos Gómez-Gallego PhD, from University of Eastern Finland, to discuss genetically modified microorganisms. They go over what genetically modified microorganisms are, their potential benefits over non-modified microorganisms, and how they might improve human health–in particular, diseases of the metabolic and immune systems.

 

Key topics from this episode:

  • Genetically modified microorganisms are those that have been modified using genetic engineering, giving them abilities they do not normally have. Functions can be either conferred or deleted. Different genetic engineering tools can be used – e.g. to make them produce therapeutic compounds, or make them increase degradation of toxins or harmful compounds.
  • One advantage over non-modified microorganisms is the potential to have continuous delivery of a therapeutic compound, and the potential to deliver it to a localized area in order to avoid unwanted interactions.
  • Genetically modified microorganisms have promise in metabolic and immune-linked disorders such as non-alcoholic fatty liver disease (NAFLD).
  • In NAFLD, genetically modified E. coli Nissle can secrete hormones that are under-regulated or under-expressed. His group modified bacteria by introducing a plasmid that allowed it to produce aldafermin, an analog of the human hormone fibroblast growth factor 19 (FGF19).
  • With genetically engineered microorganisms, we must consider the benefits but also the risks. However, if it’s a therapeutic for a disease with few or no alternatives, there’s a strong case for developing them.
  • To increase efficacy and safety of these microorganisms, it’s possible to introduce sensors that produce the therapeutic in response to different stimuli. Also, it’s important to modify the bacteria so their use is controlled and they cannot spread. They can also be modified to avoid transmission of genes.
  • Are there market-approved genetically modified microorganisms? No approved ones yet, but some are in Phase 1 and Phase 2 clinical trials.

Episode links:

About Dr. Carlos Gómez-Gallego:

I am a Senior Researcher at the Institute of Public Health and Clinical Nutrition (University of Eastern Finland). I have completed two university degrees, one in Biology and another in Food Science and Technology, and an MSc in Nutrition and Health. I subsequently completed a Ph.D. from the University of Murcia, where I investigated the effect of infant formula processing on the content of polyamines and bioactive peptides, and their impact on intestinal microbiota and immune system development during lactation.

My research and interests are primarily focused on advancing the understanding of the impact of diet, food, and bioactive compounds on human microbiota and their association with human health. As part of the BestTreat project (https://besttreat.eu/index.html), I have co-supervised two PhD students (Johnson Lok and Valeria Ianone) who evaluated the potential use of engineered E. coli Nissle 1917 producing human hormones for the treatment of non-alcoholic fatty liver disease (NAFLD) in a mouse model. The first publication has already been submitted, and the second is currently in process.

More info about my publications:
Research Gate https://www.researchgate.net/profile/Carlos-Gomez-Gallego
UEF connect https://uefconnect.uef.fi/en/person/carlos.gomez-gallego/#information

Supercharging innovation: New session at ISAPP 2023 annual meeting brings industry and student members together to scientific innovation workshop in the field of biotics

Innovation in the biotics field is an important way to address some of our most important challenges in health, and ISAPP is the organization on the forefront of this innovation. This year ISAPP members are excited to debut a new workshop focused on innovation, June 26th at the 2023 ISAPP annual meeting in Denver. For this workshop, the Industry Advisory Committee (IAC) and the Students and Fellows Association (SFA) have joined forces and initiated a new way to share knowledge and promote networking opportunities.

How did the idea of the IAC-SFA innovation workshops come about?

The Innovation Workshops evolved from interest in how SFA and IAC might gain scientific insights from each other. What they have in common is a dedication to cutting-edge science. From this emerged the idea that these groups could convene several concurrent workshop sessions during the pre-meeting program focusing on innovation in the biotic field.

What will be discussed at the workshops?

The concurrent workshops will focus on four topics:

  • Innovation in prebiotics: What’s next? Chaired by Marla Cunningham
  • Latest advances in microbiome models and biotic screening techniques. Chaired by Brendan Daisley
  • Looking to the future for food and biotics. Chaired by Daragh Hill
  • Probiotic application beyond the gut: What have we learned and what’s next? Chaired by Mariya Petrova

Guided by IAC and SFA representatives, the attendees at each workshop will discuss topics of interest and attempt to answer relevant questions in the biotics field. For example:

  • What are the latest developments in the biotic field regarding research, discoveries, and techniques?
  • What problems are we currently facing, and how will we solve them?
  • What are the future opportunities, and how can we progress?

How will this advance innovation in the field?

The Innovation Workshops will provide a platform where IAC representatives and SFA members can benefit from the exchange ideas gained from unique viewpoints expressed. Industry members can hear firsthand about innovative research that students and fellows perform in their labs, while students can gain a deeper understanding of some of the considerations for commercialization and opportunities and barriers in the marketplace. By joining forces, we believe these workshops will form a bridge between industry and young generation scientists and provide valuable insights into to the latest biotic questions.

Through initiatives such as these, ISAPP drives scientific innovation in biotics for the benefit of the entire field.

How to navigate probiotic evidence and guidelines for pediatric populations

Episode 20: How to navigate probiotic evidence and guidelines for pediatric populations

How to navigate probiotic evidence and guidelines for pediatric populations

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

How to navigate probiotic evidence and guidelines for pediatric populations, with Dr. Hania Szajewska

Episode summary:

In this episode, the ISAPP podcast hosts talk about evidence and guidelines for probiotics in pediatric populations, with Prof. Hania Szajewska MD PhD, of the Department of Paediatrics at the Medical University of Warsaw, Poland. They talk about some of the inconsistencies between different medical organizations’ guidelines for pediatric probiotic use, and how clinicians can move forward with recommendations based on the best available evidence.

 

Key topics from this episode:

  • Guidelines exist on probiotic use for gastroenterological issues in children, but there are differences (especially regarding acute gastroenteritis) between guidelines from different medical societies: European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) and The American Gastroenterological Association (AGA).
  • Realistic expectations are necessary when prescribing probiotics. Different probiotics have different benefits, but they are not a ‘magic bullet’. For example, the evidence shows certain probiotics for acute gastroenteritis reduce diarrhea by an average of one day. This could have a big impact on the quality of life of the end user, but for clinicians it may not sound like a lot so they must set expectations accordingly.
  • The market is overflowing with probiotic products, many of which do not have proven efficacy. This makes it difficult for end users and healthcare professionals to distinguish the best products.
  • Always look for evidence-based probiotics with documented efficacy for the indication for which they are intended.
    • Physicians have the ethical duty to prescribe evidence-based products (that is, clinically proven, effective products).
    • The exact strains and doses matter.
  • Formal training and education of healthcare professionals regarding the beneficial effects of microbes, the microbiome, and probiotics are currently lacking.
  • Is it more valuable to know probiotics’ mechanism of action, or to have evidence from clinical trials that they are effective?
    • Ideally we would have both, but since we don’t know the exact mechanism for all probiotics, positive evidence from clinical trials is crucial. 
    • We also need to make clear to healthcare professionals and end users what to expect from taking probiotics. For example, some probiotics reduce the chances of developing antibiotic-associated diarrhea by 50%. For colic, some probiotics can reduce the crying time by half an hour. These are modest benefits but for the affected individual they may be impactful.
  • For vulnerable populations such as preterm infants, we need high-quality products with proven safety and efficacy.

 

Episode abbreviations and links:

 

About Prof. Hania Szajewska

Hania Szajewska, MD, is Professor and Chair of the Department of Paediatrics at the Medical University of Warsaw and the Chair of the Medical Sciences Council. Among her various functions, she served as the Editor-in-Chief of the Journal of Pediatric Gastroenterology and Nutrition; a member of the Council and then as the General Secretary of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN); the Secretary of the ESPGHAN Committee on Nutrition. Most recently, she joined the Board of Directors of the International Scientific Association for Probiotics and Prebiotics (ISAPP). Prof. Szajewska has broad interests in pediatric nutrition but her research focuses on the effects of early nutritional interventions on later outcome; and the gut microbiota modifications such as with various biotics (probiotics, prebiotics, synbiotics, postbiotics). She is or has been actively involved in several European Union-funded research projects. She is an enthusiastic advocate for the practice of evidence-based medicine. Prof. Szajewska has co-authored more than 400 peer-reviewed publications and 30 book chapters. Citations >18,141. Hirsch index 72 (WoS, March 2023).

Questioning the existence of a fetal microbiome, with Dr. Kate Kennedy

Episode 19: Questioning the existence of a fetal microbiome

Questioning the existence of a fetal microbiome, with Dr. Kate Kennedy

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

Questioning the existence of a fetal microbiome, with Dr. Kate Kennedy

Episode summary:

In this episode, the ISAPP podcast hosts tackle the debate on the existence of a fetal microbiome, with guest Kate Kennedy PhD of McMaster University in Canada. They talk about Kennedy’s recent co-first-authored paper in Nature, which concludes that it is not biologically plausible that the fetus harbors live microorganisms, and that previous microbial sequencing studies on the fetal microbiome did not account for the many sources of contamination.

 

Key topics from this episode:

  • During the last 10 years, a lively debate has emerged on whether humans harbor living microorganisms prior to birth. Some scientists have looked at fetal and placental tissues and amniotic fluid, and have ostensibly detected microbial DNA. But those results are being questioned, with the argument that the signals being found are not biologically plausible.
  • Kennedy et al. published an article in Nature that re-analyzed data and brought in experts from different related fields to help interpret the data. The conclusion is that the fetal microbiome does not exist. Previous studies have likely seen contamination during sampling, since it’s nearly impossible to collect samples in a sterile way following vaginal delivery; contamination can happen at different stages so stringent controls are needed across all these areas of potential contamination. Furthermore, live microorganisms in the fetus does not fit with what we already know in related fields of science.
  • The popularity of microbiome research may have made scientists interested in this topic, although sequencing by itself may not be sufficient to settle the question of whether a fetal microbiome exists.
  • Human cells have Mitochondrial DNA, which is bacterial in origin. In 16S rRNA gene sequencing, there is some overlap in what is amplified, and this could include mitochondrial DNA, giving misleading results. This was not accounted for in some of the initial fetal microbiome studies.
  • Bringing together disparate disciplines is inherently challenging. It’s very important to work to understand each other and understand the host and biological situation you’re dealing with.
  • If there were even small numbers of bacteria present in the fetus it would have huge implications for our understanding of fetal biology and immunology. One question would be: how is the fetus limiting growth of any microbes it harbors?
  • Despite the likelihood that the fetal microbiome does not exist, the fetus is not unprepared for the microbial onslaught after birth. The maternal microbiota and immune system can educate the fetus immunologically in the absence of fetal colonization.

 

Episode abbreviations and links:

 

About Dr. Kate Kennedy

Kate completed her PhD on the role of the maternal gut microbiome in perinatal programming in the lab of Dr. Deborah Sloboda at McMaster University. She previously completed her BSc and MSc in Biology at the University of Waterloo. Her research explores host-microbiome relationships in pregnancy, early-life, and aging to understand their role in modulating health and disease risk.  

Episode 18: The definition of postbiotics

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

The definition of postbiotics, with Dr. Gabriel Vinderola and Prof. Seppo Salminen

Episode summary:

In this episode, the ISAPP podcast hosts join guests Gabriel Vinderola, PhD, Principal Researcher at the
National Scientific and Technical Research Council (CONICET) and Associate Professor at University of Litoral in Argentina, and Seppo Salminen, PhD, Professor at University of Turku in Finland, to discuss the relatively recent definition of postbiotics and what kinds of substances are included in this category. They talk about the criteria for something to qualify as a postbiotic, common mechanisms of action for postbiotics, and how postbiotic science has brought new perspectives on the study of probiotics.

 

Key topics from this episode:

  • What are postbiotics? Dr. Vinderola and Prof. Salminen dive deep into the definition of postbiotics created in 2021 and what it entails.
  • Postbiotics, similar to probiotics, prebiotics, and synbiotics, must provide health benefits to the host.
  • The nature of the postbiotic preparation is important for its health benefits. When the inactivation process is changed, this can lead to altered health benefits, and clinical studies must be repeated to ensure the desired health benefits are maintained.
  • They explain why “inanimate” was chosen to describe the microorganisms / components in a postbiotic preparation. 
  • What is the mode of action, or how do postbiotics work? 
    • Postbiotics show similar mechanisms of action to probiotics, except for ones requiring viability, since postbiotics will not grow and produce metabolic byproducts in the host.
    • Postbiotics can benefit the host via physical interaction with the host epithelial and immune cells.
    • A primary mechanism of action is likely to be through activation of the immune system, through which postbiotics can affect inflammation and some disease conditions. 
    • Postbiotics may also affect the microbiome composition and ability to inhibit pathogens.
  • From a regulatory point of view, inanimate microorganisms may represent an easier category to prove safe for users. For industry, postbiotics may be more convenient with a longer shelf life.
  • Some controversy still exists around the ISAPP-led postbiotic definition, and this has led to valuable discussions that are crucial to scientific progress. So far the authors of the definition have defended their stance.

 

Episode abbreviations and links:

 

Additional Resources:

Postbiotics. ISAPP infographic (also available in Japanese and Spanish).

Behind the publication: Understanding ISAPP’s new scientific consensus definition of postbiotics. ISAPP blog post.

Definition of postbiotics: A panel debate in Amsterdam. ISAPP blog post.

 

About Dr. Gabriel Vinderola: 

Gabriel Vinderola graduated at the Faculty of Chemical Engineering from the National University of Litoral (Santa Fe, Argentina) in 1997. He obtained his Ph.D. in Chemistry in 2002 at the same University. He collaborated with several research teams in Canada, Spain, France, Italy, Germany, Brazil and Finland. He is presently Principal Researcher of the National Scientific and Technical Research Council (CONICET) and Associate Professor at the Food Engineering Department of his home Faculty. He participated in 1999 in the development of the first commercial cheese carrying probiotic bacteria in Latin America. In 2011, he was awarded the prize in Food Technology for young scientists, by the National Academy of Natural, Physic and Exact Sciences from Argentina. He published more than 120 original scientific publications in international refereed journals and book chapters. From 2020 to present, he serves as a member of the board of directors of the International Scientific Association for Probiotics and Prebiotcis (ISAPP). He is engaged in science communication to the general public through Instagram (@gvinde).

 

About Prof. Seppo Salminen: 

Seppo Salminen, MSc, MS, PhD, is a Senior Advisor, Functional Foods Forum (FFF) at the University of Turku. His areas of expertise are gut microbiota, probiotics and prebiotics, nutrition and food safety, and EU regulations. Seppo teaches the topics of lactic acid biotechnology, functional foods and EU legislation and conducts research into food and health, intestinal microbiota, probiotics, prebiotics, functional foods, food legislation, health claims, and novel foods.

Episode 16: The honey bee microbiome and potential for probiotics

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

The honeybee microbiome and potential for probiotics, with Dr. Brendan Daisley

Episode summary:

In this episode, the ISAPP podcast hosts cover the honey bee microbiome with Brendan Daisley, PhD, who is currently a post-doctoral fellow at the University of Guelph in Canada. Daisley explains how the honeybee microbiome is unique, why it’s important for bee health, and the potential for probiotic applications as well as the practicalities of how live microorganisms are delivered to hives.

 

Key topics from this episode:

  • Daisley’s research is motivated by declining bee populations and finding ways to find ways to stop this.
  • He originally researched how probiotics could have detoxification functions in humans; this led to the question of whether probiotics could help reduce the toxicity of pesticides in bees and possibly affect resistance to infectious diseases.
  • Each individual bee has a microbiome of its own. Unlike other insects, bees have a core, defined microbial community in their guts.
  • Surprisingly, no one has successfully derived a completely germ-free honey bee. Microbiota-depleted bees do exist, however.
  • Research is ongoing on how microbes may even enable life in bee species — e.g. the recent finding that pupation in stingless bees is triggered by fungi.
  • Bees are affected by pesticides; many pesticides also have antimicrobial effects, but regulatory agencies do not track these effects.
  • Supplementing bees with beneficial strains of microbes can improve bee health and resistance to infectious diseases. However, no good baseline studies have been done on the bee gut, so it’s difficult to know what’s ‘normal’ and what is missing. The Canadian Bee Gut Project aims to determine this.
  • It’s possible to try finding bees that may have had less exposure to pesticides, but it’s difficult to determine past exposure because bees are traded and sent all over the world.
  • Wolbachia is a valuable endosymbiont for bees, and acts like a ‘secondary mitochondria’ in their cells. Currently it is hardly ever found in honey bees, possibly because of chronic exposure to tetracycline.
  • Probiotics can be delivered to bees using a “BioPatty” or a spray-based formula; the delivery method is very important. Supplementing the hive with certain probiotics can suppress outbreaks of American Foulbrood disease when they happen.
  • Daisley and colleagues used 3 probiotic strains, which remain present in the bee host for several weeks. 
  • As far as potential prebiotics for bees, it has been observed that pollen fibers can beneficially modulate the honey bee microbiome.
  • The healthy honey bee microbiome should be dominated by lactic acid bacteria.

 

Episode abbreviations and links:

 

About Dr. Brendan Daisley:

Dr. Brendan Daisley is a postdoc at the University of Guelph (Allen-Vercoe lab) and the current President of the Students and Fellows Association of ISAPP. He graduated from his PhD in Microbiology & Immunology at Western University in 2021 (supervisor: Dr. Gregor Reid), during which he received several national awards including the Armand Frappier Outstanding Student Award, adjudicated by The Canadian Society of Microbiologists. Brendan has a broad range of experience in environmental application of probiotics to honey bees and, notably, he was the first to introduce the theory of ‘missing microbes’ within the field of honey bee microbiome research. During his PhD, he helped coordinate several large field trials across North America (mostly in Ontario and California) showing that supplementation of probiotic lactobacilli strains to honey bees could improve colony-level health outcomes. During his postdoc work, he has developed a microbiome database tool (BEExact) for improved detection of uncultivated ‘microbial dark matter’, established a bioreactor model of the honey bee gut microbiome (the RoBEEgut), and co-founded the Canadian Bee Gut Project (https://beegutproject.uoguelph.ca) – a nationwide crowdsourcing initiative that aims to deeply sequence thousands of bee microbiome samples to increase our knowledge on the multifactorial drivers of honey bee mortality.

Episode 15: A primer on prebiotics

 

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 Prebiotics (ISAPP), a nonprofit scientific organization dedicated to advancing the science of these fields.

A primer on prebiotics, with Dr. Karen Scott

Episode summary:

In this episode, the ISAPP podcast hosts talk about prebiotics with Karen Scott, PhD, who is an ISAPP board member and Senior Research Fellow at Rowett Institute, University of Aberdeen, Scotland. Scott describes what prebiotics are, as well as the latest thinking about how they fit within an overall healthy diet and how they confer health benefits through the gut microbiota.

Key topics from this episode:

  • Dr. Scott and colleagues at the Rowett Institute began many years ago by working on anaerobic bacteria from the rumen of animals, then started to focus on the bacteria in the human large intestine.
  • Prebiotics (see definition below) stimulate the growth of beneficial bacteria in the human gut, and in doing so, benefit host health.
    Prebiotics alone cannot guarantee health: they must be consumed in addition to a healthy regular diet, which helps support thediversity of all gut microbes.
  • Prebiotics are not necessarily supplements; they are found in high amounts in many foods such as bulb-based vegetables, banana, and plantain. Around 5g of prebiotic per days is beneficial for health.
  • Not all prebiotics are equal: they each stimulate the growth of particular groups of bacteria. By definition, they must be selectively utilized (that is, some bacteria but not others must use them), and this differentiates prebiotics from fiber.
  • Some prebiotics are shown to improve gut transit (i.e. reduce constipation). One common example of the benefit of prebiotics has to do with bone health: metabolism of prebiotics in the colon tends to lower the pH; this increases calcium absorption for supporting bone health. Other benefits involve the production of short-chain fatty acids.
  • Bifidobacterium have traditionally been a group of bacteria targeted by prebiotics. Some Bifidobacterium produce lactate, and other bacteria produce butyrate (important for colonic health) from lactate. In healthy adults, there are bacteria that are equally or more important than bifidobacteria, however.
  • Prebiotics can target other body sites besides the gut.
  • Prebiotics that can be used by a bacteria in pure culture are not necessarily used by those bacteria within the ecosystem of the human gut.
  • New experimental platforms exist to see which bacteria are producing specific compounds on the growth of a specific substrate. But a model may not represent what is happening in the host, so this must be specifically tested.
  • Human milk oligosaccharides are a great example of how prebiotics are important to human health. Formula is often supplemented with prebiotics because of ample evidence that oligosaccharides (naturally present in human milk, but mimicked synthetically) enable growth of specific bacteria in the baby’s gut that are very important for immunity and other aspects of health.
  • Overall, to support bacteria in your gut and overall health, Dr. Scott recommends consuming a diverse diet: “eat a rainbow”. If you cannot, a prebiotic supplement is advisable.*

Episode abbreviations and links:

Dr. Karen Scott works at the Rowett Institute, a renowned centre focused on nutrition and human health.

ISAPP published the scientific consensus definition of prebiotics.

An early review co-authored by Dr. Scott, covering gut microbiota functions and their impact on host health via diet.

A review on prebiotics to support calcium absorption and therefore bone health.

Dr. Scott refers to a new tool: the Exploris 240 Orbitrap mass spectrometer, which is interfaced with an atmospheric pressure matrix assisted laser desorption ionisation (AP-MALDI) source and direct infusion. This theoretically allows scientists to measure the distribution and composition of complex gut bacterial communities, whilst simultaneously assessing metabolite production from the constituent microbes, allowing them to better understand the cooperation and competition between different human gut microbiota species.

Additional resources:

Prebiotics. ISAPP infographic.

Understanding prebiotics and fiber. ISAPP infographic.

The many functions of human milk oligosaccharides: A Q&A with Prof. Ardythe Morrow. ISAPP blog post.

 

About Dr. Karen Scott:

Dr. Karen Scott is a Senior Research Fellow at the Rowett Institute, University of Aberdeen. She leads a research team investigating the (molecular) mechanisms by which key members of the gut microbiota interact with the diet and host, at different life-stages. The fermentation products of gut bacteria contribute to gut health, and are differentially expressed on different substrates, including prebiotics. In vitro bacterial growth studies utilising our large culture collection of gut anaerobes (in pure culture, mixed culture, fermentor systems, and also with human cells) and bioinformatic analyses illustrate niche-specific processes and bacterial interactions. Resident bacteria are also an important reservoir of transferable antimicrobial resistance genes, and other work investigates the evolution and spread of resistance from farm to fork.

Looking back and looking ahead: ISAPP session focuses on the past, present, and future of the biotics field

Kristina Campbell, MSc, and Prof. Dan Tancredi, PhD, Professor of Pediatrics, UC Davis School of Medicine and Center for Healthcare Policy and Research

Twenty years ago, in 2002, the first ISAPP meeting was held in London, Canada. At the time, the field was much less developed: only small human trials on probiotics or prebiotics had been published, no Nutrition and Health Claims legislation existed in the EU, and the human microbiome project hadn’t been conceived.

Now in ISAPP’s 20th year, the scientific landscape of probiotics and prebiotics is vastly different. For one thing, probiotics and prebiotics now form part of the broader field of “biotics”, which also encompasses both synbiotics and postbiotics. Hundreds of trials on biotics have been published, regulations on safety and health claims has evolved tremendously globally, and ”biotics” are go-to interventions (both food and drug) to modulate the microbiota for health.

At the ISAPP annual meeting earlier this year, scientists across academia and industry joined together for an interactive session discussing the past, present and future of the biotics field. Three invited speakers set the stage by covering some important advancements in the field. Then session chair (Prof. Daniel Tancredi) invited the participants to divide into 12 small groups to discuss responses to a set of questions. The session was focused on generating ideas, rather than achieving consensus.

The following is a summary of the main ideas generated about the past, present and future of the biotics field. Many of the ideas, naturally, were future-focused – participants were interested in how to move the field of biotics forward with purpose.

The past 20 years in the biotics field

Prof. Eamonn Quigley had the challenge of opening the discussion about the past by summing up the last 20 years in the biotics field. He covered early microbiological progress in the biotics field, such as the production of antimicrobials and progress in understanding the biology of lactic acid bacteria and their phages. In the modern era, scientists made strides in understanding the role of gut bacteria and metabolites in hepatic encephalopathy; the role of C. difficile in pseudo-membranous colitis; and in the 90s, the concept of bacterial translocation in the intestines. Prof. Quigley summarized the progress and challenges in advancing the underlying science and in developing actionable clinical evidence. He noted that more high-quality clinical trials are being published lately.

The discussion participants noted the following achievements in the field over the past two decades:

Recognition that microbes can be ‘good’. A massive shift in public consciousness has taken place over the past 20 years: the increased recognition that microorganisms are not just pathogens, they have a role to play in the maintenance of health. This added impetus to the idea that consuming beneficial microbes or other biotics is desirable or even necessary.

The high profile of biotics. An increasing number of people are familiar with the basic idea of biotics. Especially for probiotics, there is a strong legacy of use for digestive health; they are also widely available to consumers all around the world.

ISAPP’s published papers. Participants appreciated the papers published as a result of ISAPP’s efforts, including the five scientific consensus definition papers. These have raised the profile of biotics and clarified important issues.

Connections between basic and clinical scientists. Collaborations between biotics scientists and clinicians have been increasing over the past two decades, leading to better questions and higher quality research. ISAPP is one of the leading organizations that provides opportunities for these two groups to interact.

These were among the challenges from the past two decades, as identified by discussion participants:

Lack of understanding among those outside the probiotic/prebiotic field. Although the science has advanced greatly over the past 20 years, some outside the biotics field continue to believe the evidence for probiotic efficacy is thin. It appears some early stereotypes about probiotics and other biotics persist, especially in some clinical settings. This also leads to consumer misunderstandings and affects how they use biotics substances.

Too many studies lacking in quality. In the past, many studies were poorly designed; and sometimes the clinical research did not follow the science. Further, a relative lack of mechanistic research is evident in the literature.

Lack of regulatory harmony. Probiotics and other biotics are regulated in different ways around the world. The lack of harmonized regulations (for example, EFSA and FDA having different regulatory approaches) has led to confusion about how to scientifically substantiate claims in the proper way to satisfy regulators.

Lack of standardized methodologies. Many scientific variables related to biotics, such as microbiome measurements, do not have standardized methodologies, making comparability between studies difficult.

Not having validated biomarkers. The absence of validated biomarkers was noted as a potential impediment to conducting feasible clinical research studies.

The current status of the biotics field

At the moment, the biotics field is more active than ever. The industry has grown to billions of dollars per year and microbial therapeutics are in development all across the globe. The number of published pro/prebiotic papers is over 40K and the consensus definitions alone have been accessed over half a million times.

Prof. Kristin Verbeke spoke at the interactive session about the biotics field at present. She noted that the field has faced the scientific reality that there is no single microbiota configuration exclusively associated with health. The current trajectory is to develop and expand systems biology approaches for understanding the taxonomic and functional composition of microbiomes and how those impact health. Scientists are increasingly making use of bioinformatics tools to improve multi-omic analyses, and working toward proving causation.

The future of the biotics field

Prof. Clara Belzer at the ISAPP 2022 annual meeting

Prof. Clara Belzer spoke on the future of the biotics field, focusing on a so-called “next-generation” bacterium, Akkermansia muciniphila. She covered how nutritional strategies might be based on improved understanding of the interplay between microbes and mucosal health via mucin glycans, and the potential for synthetic microbial communities to lead to scientific discoveries in microbial ecology and health. She also mentioned some notable citizen science education and research projects, which will contribute to overall knowledge in the biotics field.

Participants identified the following future directions in the field of biotics:

Expanding biotics to medical (disease) applications. One group discussed at length the potential of biotics to expand from food applications (for general overall health) to medical applications. The science and regulatory frameworks will drive this shift. They believed this expansion will increase the credibility of biotics among healthcare practitioners, as the health benefits will be medical-condition-specific and will also have much broader applicability.

As for which medical conditions are promising, the group discussed indications for which there are demonstrated mechanistic as well as clinical effects: atopic diseases, irritable bowel syndrome, and stimulating the immune system to boost vaccine efficacy. In general, three different groups of medical conditions could be targeted: (1) common infections, (2) serious infectious diseases, and (3) chronic diseases for which drugs are currently inadequate, such as metabolic disorders, mental health disorders and autoimmune diseases.

Using biotics as adjuncts to medical treatments. An area of huge potential for biotics is in complementing existing medical treatments for chronic disease. There is evidence suggesting in some cases biotics could be used to increase the efficacy of drugs or perhaps reduce side effects, for example with proton pump inhibitors, statins, NSAIDs, metformin, or cancer drugs. Biotics are not going to replace commonly used drugs, but helping manage certain diseases is certainly within reach.

Using real-world data in studies. Participants said more well-conducted studies should be done using real world data. This seems in line with the development of citizen science projects as described by Clara Belzer and others at the ISAPP meeting. Real-world data is particularly important in the research on food patterns/dietary habits as they relate to biotics.

Considering new probiotic formulations. In some cases, a cocktail of many strains (50-60, for example) may be necessary for achieving a certain health effect. Using good models and data from human participants, it may be possible to create these multi-strain formulations with increased effects on the gut microbial ecosystem and increased efficacy.

Embracing omics technology and its advancement. Participants thought the next five years should see a focus on omics data, which allows for stratifying individuals in studies. This will also help increase the quality of RCTs.

More mechanism of action studies. Several groups expressed the importance of investing in understanding mechanisms of action for biotic substances. Such understandings can help drive more targeted clinical studies, providing a rationale for the exact type of intervention that is likely to be effective. Thus, clinical studies can be stronger and have more positive outcomes.

Increased focus on public / consumer engagement. Educational platforms can engage consumers, providing grassroots support for more research resources as well as advancing regulatory frameworks. Diagnostic tools (e.g. microbiome tests with validated recommendations) will help drive engagement of consumers. Further, science bloggers are critical for sharing good-quality information, and other digital channels can have great impact.

Defining and developing “precision biotics”. One group talked about “precision biotics” as solutions that target specific health benefits, which also have a well-defined or unique mechanism of action. At present, this category of biotics is in its very early stages; a prerequisite would be to better define the causes and pathways of gastrointestinal diseases.

Increasing incentives for good science. Participants discussed altering the regulatory and market environments so that good science and proper randomized, controlled trials on biotics are incentivized. Regulators in particular need to change their approaches so that companies are driven primarily by the science.

Precise characterization of responders and non-responders. The responder and non-responder phenomenon is seen with many biotic interventions. Across the field, deep characterization of subjects using multi-omics approaches with a high resolution is needed to determine what factors drive response and non-response to particular biotics substances.

Overall, participants’ ideas centered around the theme of leaning into the science to be able to create better-quality biotics products that support the health of different consumer and patient groups.

 

Special thanks to the table discussion leaders: Irene Lenoir-Wijnkoop, Zac Lewis, Seema Mody, David Obis, Mariya Petrova, Amanda Ramer-Tait, Delphine Saulnier, Marieke Schoemaker, Barry Silkington, Stephen Theis, Elaine Vaughan and Anisha Wijeyesekera.

Episode 14: Evidence on probiotics for preterm infants

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.

Evidence on probiotics for preterm infants, with Dr. Geoffrey A. Preidis

Episode summary:

In this episode, the ISAPP podcast hosts talk about probiotics for preterm infants with Geoff Preidis, MD, PhD, a pediatric gastroenterologist and researcher at Baylor College of Medicine & Texas Children’s Hospital. Predis describes the evidence on probiotics for prevention of necrotizing enterocolitis, the challenges in interpreting the evidence that exists, and using the evidence to make clinical decisions.

Key topics from this episode:

  • Dr. Preidis works mostly with preterm infants, a population that didn’t exist just a few decades ago.
  • In the totality of evidence on probiotics for treating or preventing certain health conditions, the largest body of evidence is on whether probiotics can prevent negative health outcomes in preterm infants. Large meta-analyses (>15,000 preterm infants, >60 RCTs) conclude that overall, probiotics reduce the risk of necrotizing enterocolitis (NEC) by ~50%.
  • Probiotics do not appear to increase the risk of sepsis. In one case, contamination during the manufacturing process led to a severe infection and death. Although there is a very low risk of this happening, it highlights that a pharmaceutical grade probiotic is not available to give infants.
  • Many caveats accompany these findings, however. Trials use a wide range of products, as well as different strains, doses, durations of treatment, preterm infant populations, etc. Trials vary in their quality.
  • The body of evidence on probiotics for preventing NEC is convincing but far from perfect. Future trials need to continue reporting details on safety.
  • Some leading professional societies have issued guidelines that contradict each other.
  • How should clinicians make a decision, then? One way of choosing one therapy over another is to use network meta-analysis, which  ranks therapies according to which product might have greater efficacy than another. However, the most studied therapies tend to rank higher. 
  • Another way to make a decision is to consider looking at mechanisms. This is challenging with NEC, since we don’t know exactly what causes it.
  • Dr. Preidis is doing research on the association between early life undernutrition and increased risk of metabolic disorders later in life, what is known as the “thrifty phenotype” hypothesis. The mechanism may involve an epigenetic switch, whereby early life nutritional insult affects gene expression and metabolism in a long-lasting way.

 

Episode abbreviations and links:

This 2020 Cochrane Library review of probiotics for preventing NEC, mortality, and invasive infection (i.e. sepsis), found that “Combined analyses showed that giving very preterm and very low birth weight infants probiotics may reduce the risk of necrotizing enterocolitis, and probably reduces the risk of death and serious infection,” but also noted important concerns about the quality of the trials used to support these conclusions,  that, “further, large, high-quality trials are needed to provide evidence of sufficient quality and applicability to inform policy and practice.”

Study in JPGN showing metabolites and fecal microbiota in preterm infants are modulated according to the probiotics they are exposed to.

Network meta-analysis on how probiotics affect morbidity and mortality in preterm infants.

A recent commentary by Dr. Preidis on rational selection of a probiotic for preventing necrotizing enterocolitis

 

Additional resources:

Probiotics and Necrotizing Enterocolitis. ISAPP infographic.

Probiotics to Prevent Necrotizing Enterocolitis: Moving to Evidence-Based Use. ISAPP blog.

 

About Dr. Geoff Preidis:

Dr. Preidis received his undergraduate degree in Physics from Harvard University, then completed his medical degree, residency in Pediatrics, fellowship in Pediatric Gastroenterology, Hepatology & Nutrition, and Ph.D. in Translational Biology and Molecular Medicine from Baylor College of Medicine. Now an Assistant Professor at Baylor College of Medicine and Texas Children’s Hospital, Dr. Preidis leads the Nutritional Physiology Research Laboratory and serves as an attending physician on both the Neonatal Gastroenterology, Hepatology & Nutrition Consultation Service and the Transplant Hepatology Service.

Dr. Preidis’s laboratory seeks to define mechanisms through which early life malnutrition impairs intestinal and liver function, leading to both short-term and long-term medical problems. Current studies focus on how malnutrition slows gastrointestinal motility, alters the gut microbiome, and inhibits the liver’s ability to synthesize important substances including bile acids – all of which adversely impact child growth. This research aims to help children suffering from nutritional deficiencies caused by a wide range of medical and socioeconomic factors, including premature newborns in the neonatal intensive care unit.

Episode 13: The history of ISAPP

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 history of ISAPP, with Drs. Glenn Gibson, Mary Ellen Sanders and Irene Lenoir-Wijnkoop

Episode summary:

In this episode, the ISAPP podcast hosts talk about the history of the ISAPP organization with the organization’s three co-founders: Glenn Gibson, Mary Ellen Sanders and Irene Lenoir-Wijnkoop. The three guests recount the origins of ISAPP and the state of probiotic and prebiotic science 20 years ago when the organization was founded. They speak about some of the successes and challenges they encountered along the way, and highlight what they see as some of the key achievements of ISAPP.

Key topics from this episode:

  • The origin of the idea for ISAPP back in 1999: an organization dedicated to the science of pro- and prebiotics.
  • The annual meeting proved a key mechanism to gathering the multi-disciplinary scientists together to talk about and advance the science.
  • How ISAPP walks the line between receiving funding from industry members yet protecting scientific credibility.
  • The value that ISAPP has provided to industry members and the academic scientific community over the years.
  • How research in the field developed in the last 20 years and the questions that remain unanswered.
  • How industry members understood the importance of science 20 years ago and still do today, respecting the line between science and marketing.
  • Challenges from the last 20 years and where the field is going.

 

About Irene Lenoir-Wijnkoop:

Irene Lenoir-Wijnkoop is affiliated with the Utrecht University, specialized in public health nutrition and she provides independent consultancy services in related areas. She acts as associate editor in the Drugs Outcomes Research & Policies section of Frontiers. Through her passion for tackling preventable food-related diseases, which jeopardize healthcare resources, societies and human equity, she pioneered the field of nutrition economics.

After a first experience in clinical nutrition, she successively held assignments at the Dutch and the French subsidiaries of The Upjohn Company. When food industries initiated clinical research activities, she joined management and executive positions at the Danone Group. Besides her responsibilities, she got actively involved in ILSI Europe, in many international societies and advisory boards, primarily in the field of probiotics. She co-conceived ISAPP by enabling the first -seminal- meeting in 1999 in New York. In 2010 she was awarded with the Elie Metchnikoff Prize of Recognition.

 

About Mary Ellen Sanders:

Mary Ellen Sanders, PhD serves as the Executive Science Officer for the International Scientific Association of Probiotics and Prebiotics. She is also a consultant in the area of probiotic microbiology (www.mesanders.com). She is the current chair of the United States Pharmacopeia’s Probiotics Expert Panel, was a member of the working group convened by the FAO/WHO that developed guidelines for probiotics, and co-chairs the World Gastroenterology Organisation Guidelines Committee for practice guidelines for the use of probiotics and prebiotics for gastroenterologists. She lives in Colorado with her husband, where she enjoys her 2 grandchildren, hiking and riding her aging Morgan horse.

 

About Glenn Gibson:

Born in an ambulance parked on a roundabout outside Littlethorpe Maternity Hospital near Sunderland, UK (his dad fainted). Failed scientist at school – a trait he has successfully continued to this very day. Has poked around in people’s faeces for over 30 years and as a result, has published over 500 research papers but do not waste your time reading any of them, as you will learn nothing. Before that he did a PhD on sediment microbiology and learnt a lot about what the great population (or poopulation) of Dundee flush down their toilets. 

He has supervised over 80 PhD students and 40 postdocs, who all said he was an absolute pleasure to work with and they wished their projects had lasted 10 times as long as they did. He is a compulsive fantasist. He thinks h-factor is a hat size. Has not done a day’s work in the last decade, largely because he spends all his time reading refereeing requests from journals he has never heard of, or grant bodies wanting reviews after spending decades bouncing every single one of his*, or conference organisers asking him to travel across the world (at his own expense) to give a talk or chair a session on anything whatsoever. Helped Mary Ellen, Irene and Gregor found the organisation most people call EYE-SAPP. 

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.

Episode 7: Evidence for probiotic use in pediatric populations

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.

Evidence for probiotic use in pediatric populations, with Prof. Michael Cabana

Episode summary:

In this episode, the ISAPP hosts discuss probiotics for pediatric populations with Prof. Michael Cabana, MD, MPH, from Albert Einstein College of Medicine and The Children’s Hospital at Montefiore. Prof. Cabana starts by acknowledging the gap between the demand for probiotic interventions and the evidence that currently exists for their efficacy. He gives an overview of the challenges in designing trials on probiotic interventions for children, and summarizes what the evidence shows to date.

Key topics from this episode:

  • A concerning gap exists between the strength of evidence for probiotic interventions in children and the high demand by parents for these interventions.
  • A clinician supports clinical recommendations if they are based on multiple high-quality randomized, controlled trials in different settings. Unfortunately, this level of evidence is often missing for pediatric interventions, including for probiotics.
  • A clinician is less concerned about what regulatory category (drug, supplement) a recommendation falls into, and more about the level of evidence supporting its use.
  • At a minimum, a clinician looks first for evidence of no harm.
  • Conducting clinical trials in children presents many challenges. What are the “5 Ds”, which make clinical studies in children different from those in adults, as described by Forrest in 1997?
  • A lot of adult diseases have roots in childhood, so understanding pediatric health is important not just for kids, but also for adults. Preventing adult disease starts at an early age. This is the ‘delayed payoff’ that Forrest refers to.
  • Compelling evidence exists for probiotic efficacy in children for a few endpoints: colic, antibiotic-associated diarrhea, and necrotizing enterocolitis.
  • When it comes to necrotizing enterocolitis, strong evidence, reproducibility, dose-response, and biological mechanisms are what give clinicians the confidence to use probiotics.
  • An individual patient data meta-analysis (a project that emerged from an ISAPP meeting), enabled combining data from numerous studies that looked at the probiotic L. reuteri DSM17938 given to babies with colic. An overall positive effect was seen. Factors that predicted success in infants were being formula-fed, being younger, and not being on proton pump inhibitors.

 

Episode links:

  • One of many reports on the growing market for probiotic products for infants and children 
  • Information about the 2003 Pediatric Research Equity Act (PREA) and the Best Pharmaceuticals for Children Act (BPCA) mentioned in the podcast 
  • The 5 “Ds” in Pediatrics mentioned in the podcast
  • The TIPS study mentioned in the podcast is described here and here
  • The meta-analysis on colic mentioned in the podcast

 

Additional resources:

ISAPP Digs Deeper into Evidence on Probiotics for Colic with New Meta-Analysis. ISAPP blog
Probiotics to Prevent Necrotizing Enterocolitis: Moving to Evidence-Based Use. ISAPP blog

 

About Prof. Michael Cabana, MD:

Prof. Michael Cabana, MD, MPH, is a Professor of Pediatrics & the Michael I. Cohen University Chair of Pediatrics at Albert Einstein College of Medicine, as well as Physician-in-Chief, The Children’s Hospital at Montefiore (CHAM). He is also a member of the United States Preventive Services Task Force USPSTF (here), a prestigious appointment for medical personnel to weigh evidence (risk vs. harms) on prevention interventions recommended in the United States. He is a clinical trialist (see the trials listed here), with a focus on allergy in children. He has also conducted trials using probiotic interventions. Prof. Cabana served on the ISAPP board of directors from 2008 to 2018. He has an MD from University of Pennsylvania, an MPH from Johns Hopkins, and an MA in business from Wharton Business School.

Dr. Cabana’s comments do not necessarily reflect the views of the USPSTF.

Episode 6: Mechanisms of action for probiotics

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.

Mechanisms of action for probiotics, with Prof. Sarah Lebeer

Episode summary:

In this episode, the ISAPP hosts speak with Prof. Sarah Lebeer of University of Antwerp, Belgium, to bring clarity to a commonly misunderstood topic: probiotic mechanisms of action. They discuss how probiotic mechanisms are often multi-factorial and difficult to unravel scientifically. Nevertheless, Prof. Lebeer describes five distinct mechanisms of action by which a probiotic may benefit a host.

See ISAPP’s other podcast episode on mechanisms of action, with Prof. Maria Marco: Why mechanistic research on probiotics is captivating and important.

Key topics from this episode:

  • Probiotics are live microorganisms with documented health benefits; their mode of action is multifactorial.
  • Mechanism of action is crucial in the probiotic field. This knowledge helps scientists understand how probiotics interact with the human host and the microbiota. However, even if mode of action for a strain is known it can be difficult to translate it into measurable outcomes for the host.
  • Probiotics can benefit health by five main mechanisms of action applicable at different body sites (gut, vagina, skin, nose, etc.):
    1. Modulation of microbe-microbe interactions by inhibiting pathogens and promoting beneficial microbes. This is based on the production of metabolically active molecules, such as lactic acid. 
    2. Enhancement of mucosal barrier function through interaction with epithelial cells, promoting the integrity of the barrier. 
    3. Modulation of immune responses by interacting with various immune cells. Interaction with the immune cells is also the clearest strain-specific capacity of probiotics.
    4. Modulation of metabolic responses by modulating insulin resistance or cholesterol metabolism. This mode of action is novel, and research is emerging.
    5. Modulation of neurological signaling pathways. This is also a novel mode of action with new evidence building up.
  • Postbiotics can have similar modes of action, provided the active molecules are not inactivated.

 

Episode links:

The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic

 

Graphical summary of 5 main mechanisms of action for probiotics

(Image by Sarah Lebeer. Image copyright.)

 

Additional resources:

Current status of research on probiotic and prebiotic mechanisms of action. ISAPP blog
Importance of understanding probiotic mechanisms of action. ISAPP blog

 

About Prof. Sarah Lebeer:

Sarah Lebeer is a research professor at the Department of Bioscience Engineering of the University of Antwerp, Belgium. She has studied bioscience engineering, with a specialisation in cell and gene technology/food & health and obtained her Master at KU Leuven (Belgium). In 2008, she obtained a PhD degree with a topic on the mode of action of gastro-intestinal probiotics in inflammatory bowel diseases and a scholarship in the team of Prof. Jos Vanderleyden (KU Leuven). After a postdoc on the interaction between lactobacilli, viruses and mucosal immunology, in November 2011, she was offered a tenure track position at the University of Antwerp. Since then, she is leading the Laboratory for Applied Microbiology and Biotechnology of the ENdEMIC research group.

In 2020, she was awarded with an ERC Starting Grant that enables her to gain more in-depth knowledge of the evolutionary history and ecology of lactobacilli (https://www.lebeerlab.com). This rationale was also an important driving force to revise the Lactobacillus genus taxonomy with  a large international consortium. Within the ERC project, Sarah has also launched the Isala citizen-science project to gain new insights in the role of vaginal lactobacilli for women’s health (https://isala.be). Since 2018, Sarah is an academic board member of the International Scientific Association on Probiotics and Prebiotics (www.isappscience.org). Communicating about beneficial microbes and probiotics for experts and laymen is an important inspiration for her daily work. 

Episode 5: Prebiotics for animal health

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.

Prebiotics for animal health, with Prof. George Fahey

Episode summary:

The hosts discuss prebiotics for animals with Prof. George Fahey, a prominent animal nutrition scientist who is currently Professor Emeritus at University of Illinois. Fahey explains how animal nutrition research relates to human nutrition research, and the changes in the field he has seen over the course of his long career. He describes the research on prebiotics for animal nutrition, covering both livestock and companion animals.

Key topics from this episode:

  • A short history of animal prebiotics research as well as future opportunities in animal nutrition.
  • Pro- and prebiotics are being explored as an alternative to antibiotic treatment in production animals. Antibiotics are overused, leading to an increase in antibiotic resistance; the “biotics” therefore have great potential in animal nutrition.
  • Probiotics can potentially be used instead of antibiotics to inhibit pathogens and support the gut microbiota in animals.
  • Prebiotics possibly have high nutritional value and beneficial effects in animals, especially in poultry and pigs.
  • There are limitations to using prebiotics in the animal industry, especially for some animals such as horses and ruminants.
  • There has been increased use of prebiotics for companion animals (pets) in the past few years. Now many pet foods contain prebiotics.
  • Benefits of using prebiotics in companion animals:
    •  Support digestive health
    •  Improve stool quality
    • Support the gut microbiota, which also translates to good stool quality
  • A short overview of how companion animals’ food is produced, and the timing of adding prebiotics.
  • Wild animals’ diet has low nutrition with limited to no prebiotic intake, resulting in a shorter lifespan in comparison with companion animals
  • Some take-home points from animal models and animal nutrition research.

 

Episode links:

Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics
The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic

 

Additional resources:

Are prebiotics good for dogs and cats? An animal gut health expert explains. ISAPP blog post
Using probiotics to support digestive health for dogs. ISAPP blog post
Prebiotics. ISAPP infographic

 

About Prof. George Fahey:

George C. Fahey, Jr. is Professor Emeritus of Animal Sciences and Nutritional Sciences at the University of Illinois at Urbana-Champaign. He served on the faculty since 1976 and held research, teaching, and administrative appointments. His research was in the area of carbohydrate nutrition of animals and humans. He published numerous books, book chapters, journal articles, and research abstracts.

He currently serves on two editorial boards, numerous GRAS expert panels, and is scientific advisor to both industry and governmental organizations. He retired from the University in 2010 but continues to serve on graduate student committees and departmental search committees. He owns Fahey Nutrition Consulting, Inc. that provides services to the human and pet food industries.

Episode 4: Weighing evidence for probiotic interventions: Perspectives of a primary care physician

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.

Weighing evidence for probiotic interventions: Perspectives of a primary care physician, with Prof. Dan Merenstein, MD

Episode summary:

In this episode, the ISAPP host Prof. Dan Tancredi discusses evidence for probiotic interventions with Prof. Dan Merenstein, MD, a family medicine researcher based at Georgetown University. They discuss what it means to practice evidence-based medicine, and what kind of evidence clinicians should look for when deciding whether an intervention is appropriate. Prof. Merenstein shares how probiotic evidence has strengthened in the past few decades, and gives tips on what to look for in a probiotic intervention study.

Key topics from this episode:

  • What is evidence-based medicine, and why is it important to practice it? Evidence-based medicine provides proper care for patients at the appropriate time by focusing on the existing evidence provided by clinical studies.
  • What is evidence, and how do we obtain a high level of evidence for probiotics? Evidence should come from well-designed clinical studies. Animal and in vitro studies provide supportive preclinical information and mechanistic insights.
  • The quality of probiotic research has improved in recent years. Compared with decades ago, studies are more likely to be high quality and more likely to be properly-powered. Such studies have provided a clearer sense of the circumstances under which probiotics may – or may not – provide health benefits.
  • What is the proper way to report clinical trials in the probiotic field? Focus on the rules for conducting a clinical trial: for example, CONSORT (see below). Compliance is also important for good outcomes.
  • How can a clinician evaluate if a patient should use an intervention? The focus should be on the evidence for each intervention, the potential harm of the intervention, and the positive and negative outcomes.
  • Evidence-based medicine also needs to account for regional differences and where the clinical studies have been performed. Evidence about probiotic effects needs to account for microbiome differences and lifestyle differences between countries.
  • For which indications do we now have actionable evidence for probiotic use?
    • Use of certain probiotics together with antibiotic treatment to prevent antibiotic-associated diarrhea
    • Use of an L. reuteri strain to reduce crying time for infants suffering from colic
    • Certain probiotics can help prevent traveler’s diarrhea or treat acute pediatric infectious diarrhea.
    • Probiotics to help with endpoints such as weight loss and metabolic syndrome, for autism and gut-brain indications, for skin conditions such as eczema and acne, and inflammatory bowel disease are active areas of research and soon scientists will have more answers.
  • Probiotic research is improving. Patients are using probiotics, and they are aware of the benefits of probiotics – Prof. Merenstein estimates that 80% of his patients are taking a probiotic. The job of the doctor is to get them to use probiotics in an evidence-based manner.

 

Episode links:

CONSORT (Consolidated Standards of Reporting Trials) establishes a well-accepted, evidence-based, minimum set of recommendations for reporting randomized trials.
IPDMA (individual patient data meta-analysis) – see this Sung et al. paper on infantile colic and L. reuteri
BB12: Bifidobacterium animalis subsp. lactis BB-12, a well-studied probiotic. See this paper.
A priori: without prior knowledge

 

Additional resources:

The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic

 

About Prof. Dan Merenstein:

Dr. Daniel Merenstein is a Professor with tenure of Family Medicine at Georgetown University, where he also directs Family Medicine research. Dr. Merenstein has a secondary appointment in the undergraduate Department of Human Science, in the School of Nursing and Health Studies. Dr. Merenstein teaches two undergraduate classes, a research capstone and a seminar class on evaluating evidence based medical decisions. He has been funded by the NIH, USDA, Foundations and Industry, for grants over $100 million. Dr. Merenstein is the President of the board of directors of the International Scientific Association of Probiotics and Prebiotics.

The primary goal of Dr. Merenstein’s research is to provide answers to common clinical questions that lack evidence and improve patient care. Dr. Merenstein is a clinical trialist who has recruited over 2,100 participants for 10 probiotic trials since 2006. He is an expert on probiotics, antibiotic stewardship in outpatient settings and also conducts HIV research in a large women’s cohort. He sees patients in clinic one day a week.