The microbiota is the set of bacteria that populate our gut. We are immediately led to think that the role of microbiota is limited to digestion, but in fact more and more scientific studies are demonstrating the role of the microbiota in various other processes that take place in our body and that determine the efficiency of the immune system, the presence or not of chronic inflammation, the body weight, the mood, cancer and even heart health. In particular, the article of the month selected by the Nutrition Society of Cambridge University reports the results of a research that demonstrates how the microbiota, in case of a diet rich in food of plant origin, can help prevent heart disease (Naghipour et al, Nutr Res Rev, 2020).
Based on previous studies, it has been observed that when eating foods of animal origin, such as meat, fish, eggs, milk and dairy products, the bacteria in the microbiota can metabolize the substances contained in these foods by producing toxic by-products called trimethylamines or TMA. The body tries to get rid of these substances by absorbing them and putting them into the blood in order to direct them to the liver. The liver then converts the trimethylamines into other, easier to eliminate substances called trimethylamines N oxide or TMAO. The point is that high TMAO levels have been shown to cause damage to the heart and blood vessels, and that people with cardiovascular disease have high TMAO values. It is likely that, as heart disease progresses, the body produces and retains more TMAO than a healthy person, and, when these substances exceed a threshold considered critical, they begin to damage the cardiovascular system. So TMAO are both a consequence and then also the cause of worsening heart disease, this is the conclusion of the researchers. Therefore, the advice of the author of the study is, in order to protect heart health, to limit the intake of foods of animal origin and to prefer plant based foods. In fact, it has been observed that in people who follow a vegetarian diet, the intestinal bacterial flora changes to such an extent that, even if these people occasionally consume food of animal origin, there is no production of TMA and therefore of TMAO. In fact, the vegetarian diet has ensured that the bacteria that produce TMA are replaced by those that do not produce these substances.