The composition and richness of the gut microbiota differentiate the top Polish endurance athletes from sedentary controls.

BACKGROUND

Little data are available on the subject of gut microbiota composition in endurance athletes as well as connections between diet and specific bacteria abundance. However, most studies suggest that athletes' microbiota undergoes major alterations, which may contribute to increased physical performance. Therefore, we decided to investigate differences in gut microbiota between healthy controls and endurance athletes.

MATERIALS AND METHODS

Stools samples were collected from 14 marathon runners, 11 cross-country skiers and 46 sedentary healthy controls. The athletes' diet evaluation was performed with 24-h diet recall, using the Aliant programme. The 16S gene sequencing was performed using the Ion 16S Metagenomics Kit on Ion Torrent PGM sequencer. Taxonomic classification and diversity indices computation was performed with Mothur.

RESULTS

20 and 5 taxa differentiated healthy controls from marathon runners and cross-country skiers, respectively. Both groups presented a lowered abundance of major gut microbiota genus, and higher abundance of . The athletes' microbiome was also more diverse in cross-country skiers than the one of sedentary controls (Simpson index -value at 0.025). Thirty-one strong correlations (Spearman's coefficient > 0.6) were uncovered between bacteria abundance and diet, including inverse correlation of with sucrose intake, with polyunsaturated fatty acids as well as positive correlation of with folic acid intake and with fiber amount in diet.

CONCLUSIONS

The excessive training associates with both differences in composition and promotion of higher bacterial diversity. Taxons enriched in athletes are known to participate in fiber fermentation.