Did you know that each of us has a complex community of microorganisms (bacteria, viruses, and fungi) called “microbiota” that live inside our gut? I discovered this during my PhD, this sparked my interest and I quickly began learning about this new-ish research area that has emerged over the last decades. In 2017, I joined the APC Microbiome Ireland team to do a postdoc to investigate the effect of secondary bile acids on gut maturation during the first stages of life. APC Microbiome is a diverse cross-disciplinary leading research centre to explore the microbiome’s role on the interface of health, medicine and food.
Today, it is well known that our microbiota has key functions in our body including the development of the immune system, metabolisms and maturation of the intestinal tract. As a result, the maintenance of an adequate gut microbiota is fundamental in the maintenance of those beneficial effects. More and more research has focused on finding strategies to manipulate the gut microbiota to maximize the beneficial health effects for humans.
One way to help our microbiota to maintain “healthy” is through the consumption of prebiotics (nutrients like fibres that help the growth of beneficial bacteria) and probiotics (“live microorganisms, which when administered in adequate amounts, confer a health benefit on the host”1). It is important to highlight that the microbial composition is like a fingerprint meaning that it is unique for each individual. This means that individuals will benefit differentially from these –biotics.
There is great variability in the gut microbiota profile between individuals – each person’s microbiota is like their fingerprint – unique to them. It is therefore logical to think that after the consumption of certain foods or medicines, not all individuals produce the same compounds and therefore the benefit will be different between individuals. For example, the consumption of soybeans has been largely associated with health benefits. Soybeans are rich in daidzein, a polyphenol that is used by gut microbiota to produce equol. This compound is a postbiotic that has several beneficial health effects such as antioxidant activity. However, dietary intervention studies have shown that not everyone is able to produce this compound. This means that it doesn’t matter how much soybeans they eat – they are deprived of the possible health benefits of this secondary metabolite2,3.
In recent years, research on microbiota has led to an increasing interest on the so-called postbiotics. Postbiotics, also known as secondary metabolites, can be defined as compounds produced by gut bacteria that have beneficial effects on our health4. Basically, it refers to bacterial “waste” that surprisingly have a beneficial effect on our health. Some of the most well-known postbiotics include short-chain fatty acids (butyric acid or acetic acid among others), vitamins, aminoacids, urolithins or equol. Several trials both in vitro (using cells) and in vivo (using animal models) have described the beneficial effects of these compounds such as maintenance of the gastrointestinal tract health, anti-inflammatory properties or protection against pathogens (bacteriocins).
There is a lack of sufficient numbers of intervention studies to evaluate health benefits and safety the promising use of postbiotics as strategy to improve host health has led to increased research on the mechanisms of action. Advances in gut microbiota research could contribute significantly to allowing us to in the future design personalized recommendations in order to maximize the beneficial effects of these compounds.