The future is microbial: A post-pandemic focus on identifying microbes and metabolites that support health

By Prof. Maria Marco, Department of Food Science and Technology, University of California Davis, USA

The COVID-19 pandemic has been a sobering reminder of the significance that microorganisms have on human life. Despite the tremendous scientific and medical advances of the twentieth century, our best precautions against the virus have been to practice the oldest and most simplistic of all public health measures such as washing hands and maintaining physical distance from others. At the same time, the effectiveness of the new SARS-CoV-2 vaccines and the speed in which they were developed show how sophisticated and advanced our understanding of viruses has become. Taken together, the limitations and successes of responses to the pandemic underscore the power of investment in microbiology research. This research, which was first catalyzed by the pioneering work of Louis Pasteur, Robert Koch, and contemporaries in the late 1800s, was the basis for the overall reduction in infectious diseases during the twentieth century. Continued investment in these efforts will prepare us for the next pandemic threat.

Beyond pathogens to health-promoting microbes

As our attention turns to the promise of the New Year, we may also take this moment to appreciate the fact that microorganisms can also do good. Our “microbial friends” were first promoted by the lauded biologists Élie Metchnikoff, Henry Tissier, and Issac Kendall at the turn of the twentieth century. Since then, nearly another century passed before the power of microorganisms to benefit human health reached wider acceptance.

Marked by the emergence of laboratory culture-independent, nucleic-acid based methods to study microbial communities, there is now excitement in the identification of microorganisms that are important for health promotion. This interest is catalyzed by the urgency to find ways to prevent and treat cardiovascular diseases, cancers, and other non-communicable, chronic conditions that are now the leading causes of death worldwide. Much like the pressure to address infectious diseases as the primary cause of mortality prior to the twentieth century, so too is the need today for sustained research investments in studying how certain microorganisms contribute to, or may be essential for, preventing and treating the greatest threats to public health in the modern era.

Exemplified by the growing number of human microbiome studies, it is now broadly understood that the human microbiome contributes positively to digestive, immune, and endocrine systems function. Systematic reviews and meta-analyses of clinical trials support the use of probiotics for a variety of conditions and there are positive associations between the consumption of fermented dairy foods and good metabolic health. To understand how microbes can be beneficial, numerous mechanisms have been proposed (for example, modulation of the immune system and production of neurochemicals that can impact the gut-brain axis), and these mechanisms apply to both autochthonous microbiota and probiotics alike. However, our understanding of exactly how this occurs lags far behind what is currently known about microorganisms that cause harm.

Identifying microbes & metabolites that maintain health

The future of beneficial microbes is in identifying the specific, health-promoting metabolites, proteins, and other compounds that they make. Presently only a handful of such examples are known. Perhaps most recognized are the short chain fatty acids, butyrate, propionate, and acetate, which are known to bind specific human cell receptors to modulate numerous cell pathways including those that affect metabolism. Other microbial compounds generated as intermediate or end products of microbial metabolism (such as metabolites of amino acids), secondary metabolites (such as bacteriocins), and bacterial cell surface constituents (such as certain membrane proteins) were shown to benefit health, although a more complete description of mechanistic details for their effects remains to be discovered. Precise mechanistic descriptions of “beneficial factors”, or the microbial enzymatic pathways and molecules that induce desired cellular and systemic responses in the human body, will be pivotal for elucidation of the precise ways microorganisms sustain health and well-being (for more detail on this topic see here).

Based on what we know about the complexity of the human microbiome and the now many decades of probiotics research, this effort will require innovation and multi-disciplinary coordination. Just as early microbiologists raced to address the high rates of mortality due to microbial pathogens, we are in a new age where again microorganisms are regarded as emerging public health threats. However, we now have to our advantage the knowledge that not all microorganisms cause harm but instead the majority may offer solutions to the greatest health challenges of the twenty-first century.



ISAPP’s 2019 annual meeting in Antwerp, Belgium: Directions in probiotic & prebiotic innovation

Kristina Campbell, Microbiome science writer, Victoria, British Columbia

We live in a time when a simple Google search for ‘probiotics’ produces over 56.8 million hits; a time when almost everyone has heard of probiotics through one channel or another, and when an ever-increasing variety of probiotic and prebiotic products is available in different regions of the world.

The next five to ten years will be telling: will probiotics and prebiotics join the ranks of other trendy health products that experienced a wave of popularity before something else took their place? Or will they be recognized as important contributors to health through the lifespan, and establish a permanent position in the clinical armamentarium?

According to the global group of 175 academic and industry scientists who met for the ISAPP annual meeting in Antwerp (Belgium) May 14-16, 2019, one thing above all is necessary for the world to recognize the significance of probiotics and prebiotics for health: scientific innovation. Not only are technological capabilities advancing quickly, but also, new products are being evaluated by better-educated consumers who demand more transparency about the health benefits of their probiotics and prebiotics.

Participants in the ISAPP conference came together to talk about some of the leading innovations in the world of probiotics and prebiotics. Here are three of the broad themes that emerged:

Better health through the gut-brain axis

Gut-brain axis research is rapidly growing, with many investigators in search of probiotic and prebiotic substances capable of modulating brain function in meaningful ways. Phil Burnett of Oxford (UK) presented on “Prebiotics, brain function and stress: To what extent will prebiotics replace or complement drug therapy for mental health?”. Burnett approached the challenge by administering prebiotics to healthy adults and giving them a battery of psychological tests; in one experiment he found people who consumed a prebiotic (versus placebo) showed benefits that included reduced salivary cortisol and positively altered emotional bias. For those with diagnosed brain disorders, Burnett concludes from the available data that prebiotics have potential anxiolytic and pro-cognitive effects in these populations, and that prebiotics may eventually be used to complement the established treatments for some mental disorders.

Short-chain fatty acids (SCFAs) are of interest as potential modulators of brain function, but so far very little research has been carried out in this area. Kristin Verbeke of Leuven (Belgium) gave a talk entitled “Short-chain fatty acids as mediators of human health”, which covered the extent to which interventions with fermentable carbohydrates can alter systemic SCFA concentrations (rather than gut SCFA concentrations)—since the former are more relevant to effects on the brain.

Also, a students and fellows feature talk by Caitlin Cowan of Cork (Ireland) explored a role for the microbiota in psychological effects of early stress. She spoke on the topic “A probiotic formulation reverses the effects of maternal separation on neural circuits underpinning fear expression and extinction in infant rats”.

A clear definition of synbiotics

Immediately before the main ISAPP meeting, a group of experts met to propose a consensus definition of ‘synbiotic’, with the objective of clarifying for stakeholders a scientifically valid approach for the use of the increasingly-popular term. A key point of discussion was whether the probiotic and prebiotic substances that make up a synbiotic are complementary or synergistic. And if the two substances have already been tested separately, must they be tested in combination to give evidence of their health effect? The group’s conclusions, which will undoubtedly steer the direction of future R&D programs, will be published in a forthcoming article in Nature Reviews Gastroenterology & Hepatology.

Probiotics and prebiotics for pediatric populations

Probiotics and prebiotics have been studied for their health benefits in pediatric populations for many years, but in this area scientists appear to have a renewed interest in exploring new solutions. Maria Carmen Collado of Valencia (Spain) covered “Probiotic use at conception and during gestation”, explaining some of the most promising directions for improving infant health through maternal consumption of probiotics.

In recent years, technical advancements have made possible the large-scale production of some human milk oligosaccharides (HMOs); it is now an option to administer them to infants. Evelyn Jantscher-Krenn of Graz (Austria) presented a novel perspective on HMOs, with “HMOs in pregnancy: Roles for maternal and infant health”, giving a broad overview of the many ways in which HMOs might signal health status and how they might be fine-tuned throughout a woman’s pregnancy.

A discussion group on “prebiotic applications in children”, chaired by Dr. Michael Cabana of San Francisco (USA) and Gigi Veereman of Brussels (Belgium), discussed evidence-based uses of prebiotics in children in three areas: (1) prevention of chronic disease; (2) treatment of disease; and (3) growth and development. While the latter category has the best support at present (specifically for bone development, calcium absorption, and stool softening), the other two areas may be ripe for more research and innovation. The chairs are preparing a review that covers the outcomes of this discussion group.

Next year in Banff

ISAPP’s next annual meeting is open to scientists from its member companies and will be held on June 2-4, 2020 in Banff, Canada.


Photo by Copyright, ISAPP 2019.