The intensive physical activity causes changes in the composition of gut and oral microbiota.

This study aimed to compare the gut and oral microbiota composition of professional male football players and amateurs. Environmental and behavioral factors are well known to modulate intestinal microbiota composition. Active lifestyle behaviors are involved in the improvement of metabolic and inflammatory parameters. Exercise promotes adaptational changes in human metabolic capacities affecting microbial homeostasis. Twenty professional football players and twelve amateurs were invited to the study groups. Fecal and oral microbiota were analyzed using next-generation sequencing of the 16S rRNA gene. Diversity in the oral microbiota composition was similar in amateurs and professionals, while the increase in training intensity reduced the number of bacterial species. In contrast, the analysis of the intestinal microbiota showed the greatest differentiation between professional football players and amateurs, especially during intensive training. Firmicutes were characterized by the largest population in all the studied groups. Intensive physical activity increases the abundance of butyrate and succinate-producing bacteria affecting host metabolic homeostasis, suggesting a very beneficial role for the host immune system's microbiome homeostasis and providing a proper function of the host immune system.