Gut microbiota composition between runners and cyclists may be sport-specific
Description
To date, gut microbiota composition has not been fully investigated in endurance athletes from different fields, like cyclists vs. runners. We aimed to determine the gut microbiota composition in cyclists and runners, both females and males. Are the gut bacteria expressed in runners and cyclists correlated with exercise performance, such as Vo2max, time to exhaustion, and blood lactate levels? Methods: Our study included 58 subjects, of which 22 were runners (13 males and nine females), 18 cyclists (9 males and nine females), and 18 control subjects (9 males and nine females) active but not competitive (non-cyclists non-runners). Fecal specimens were collected and analyzed for taxonomic profiling to compare species' relative abundances between subjects based on the results of 16S rRNA analysis. Bacterial beta diversity was assessed to determine the differences in microbial composition between runners, cyclists, and controls, as well as between sexes. Each participant underwent a maximal oxygen consumption test and a time-to-exhaustion test at 85% of the measured VO2max. Blood lactate was collected every 5 minutes during the tests. Results: Alpha diversity showed a significant difference (P=0.0009) between runners and cyclists. Among the cyclists, a significant difference was observed (P = 0.0009) between female cyclists and male cyclists. Bacterial beta diversity significantly differed in microbial compositions between runners and cyclists (p = 0.002). Taxonomic analysis of gut microbiota composition between runners, cyclists, and controls showed a lower or higher abundance of fifteen different bacteria. In runners, there was a significant positive correlation between ten bacteria, and in cyclists, there was a significant positive correlation between eight bacteria, with blood lactate levels, Vo2max, time to exhaustion, and weekly training volume. Conclusion: The gut microbiome signature of athletes, cyclists vs. runners, appears to be sport-specific. These findings emphasize the differences in gut microbiota between runners and cyclists, probably due to the difference in physiological and biomechanical conditions related to the activity mode during training.