An athletic intestinal microbiota?

A growing number of studies underline the benefits of physical exercise for the composition and diversity of the intestinal microbiota. But what about professional athletes? How does this ecosystem influence their performance?


Although relatively stable, the composition of the intestinal microbiota can evolve, favorably or unfavorably, due to multiple factors (diet, environment, health status, medication, etc.), with an impact on the metabolism. Studies have already shown the beneficial effects of physical exercise on its composition and diversity. But what about the intensive training of professional athletes? A team of Polish researchers tried to answer this question, comparing the microbiota of 14 marathon runners and 11 cross-country skiers with that of 46 sedentary subjects. Their objective was to determine whether there is any link between training level and bacterial composition.

A richer and more diversified microbiota

The intestinal microbiota of the high-performance athletes was richer and more diversified overall, ensuring better resistance to various diseases. This was all the more so when their diet was high-calorie and rich in nutrients (especially zinc and copper). As heavy consumers of vegetables and starchy foods, the professional athletes harbored more of the bacteria involved in breaking down fiber in their digestive tracts.

An influence on athletic performance?

Their microbiota was also richer in bacteria belonging to the large Firmicutes family and poorer in Bacteroidetes. According to a recent study, a high F/B ratio is associated with high oxygen consumption (VO2 max), which is essential to high-level athletes. Prevotella bacteria were also abundant in the athletes. They are associated with enhanced physical performance and were particularly common in the marathon runners. Another difference was the increased production, in the athletes, of certain molecules thought to improve degradation of sugars and fats and to enhance performance during strenuous exercise. So, does the level of training influence the composition of the microbiota? For the authors, the former shapes the latter, and the latter, in turn, contributes to the level of athletic performance.



Kulecka M, Fraczek B, Mikula M, et al. The composition and richness of the gut microbiota differentiate the top Polish endurance athletes from sedentary controls. Gut Microbes. 2020;11(5):1374-1384.