If you were to take a gram of your own faeces and analyse it, you would discover that it contains a greater number of bacteria than there are humans on the planet. As surprising as it may seem, it’s true that the human body is home to over 100 trillion microorganisms, which, if gathered together on a scale would weigh around 2kg. They live mainly in the colon, feeding on what we eat and leave over for them, e.g. fibres. We could say we offer them bed and board. In return, they break down some components in food that we are not able to digest – like certain types of fibre – as we lack the tools to do it ourselves. Among the produced molecules, we could highlight the short-chain fatty acids that supply energy to the gut cells and train our immune system. These bacteria even produce some vitamins that we need. Therefore, this tiny world is essential for our health.
It is known that there is a very close relationship between our diet and the diversity and balance of the community of bacteria we host, which has repercussions on our digestive health. In fact, this was one of the key topics discussed at the Gut Microbiota for Health World Summit, which took place in Barcelona in March. A balanced diet helps promote a well-structured microbiota, in which the different species of microorganisms coexist in a system of control and balance.
Due to their beneficial effects, prebiotics and probiotics can help foster the health of our gut microbiota. Therefore, experts recommend incorporating them into our diet on a regular basis. As foods for bacteria, prebiotics are functional non-digestible food components (such as certain kinds of fiber) that stimulate the activity or the growth of some specific groups of bacteria, e.g. bifidobacteria and lactic acid bacteria. A good example is inulin, a substance found in endives, onions, asparagus and artichokes.
According to the definition given in 2001 by the Food and Agriculture Organization of the United Nations (FAO) together with the World Health Organization (WHO), they are “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”. Some have formed part of the traditional diet of certain regions of the world, for example the fermented dairy products consumed in many countries.
Some probiotics have been shown to have a highly beneficial effect on health, particularly that of the gut like helping to strengthen the body’s defenses by enhancing the immune system; helping to regulate intestinal motility; and improving the microbial balance in the gut, enhancing its stability and diversity.
Due to the latest scientific discoveries about the benefits of probiotics and to avoid confusion about the use of this term, the International Scientific Association for Probiotics and Prebiotics (ISAPP) has created a series of recommendations for the scope of application and adequate use of the term “probiotic”. During the 4th Gut Microbiota for Health World Summit, the consensus document published in 2014 was presented. In this document, it was explained that dead microbes and microbial products, such as metabolites and microbial components are not considered to be probiotics. According to ISAPP’s consensus document, presented by its president, Professor Colin Hill, “‘probiotic’ should only be used to describe those products that provide microorganisms with a viable count of well-defined strains and with reasonable prospects of favouring the wellbeing of the consumer.”
During this conference, a guide was also presented, published by the European Society for Primary Care Gastroenterology (ESPCG), to provide GPs with information on recommending probiotics to their patients. This is especially pertinent in cases of people who suffer from Irritable Bowel Syndrome (IBS) and antibiotic-associated diarrhoea. This guide includes a list of 32 specific probiotics, detailing their function, the conditions for which they are most appropriate and the recommended dosage.
It is clear that nutrition plays a primary role in taking care of our gut microbiota and we are sure to carry on seeing research and news stories on the benefits of probiotics and prebiotics. We will continue to keep you informed on the latest developments via this blog.