AbstractExercise can influence gut microbial community structure and diversity; however,
the temporal dynamics of this association have rarely been explored. Here we
characterized fecal microbiota in response to short term changes in training
volume. Fecal samples, body composition, and training logs were collected from
Division I NCAA collegiate swimmers during peak training through their in-season
taper in 2016 (n=9) and 2017 (n=7), capturing a systematic
reduction in training volume near the conclusion of their athletic season. Fecal
microbiota were characterized using 16S rRNA V4 amplicon sequencing and
multivariate statistical analysis, Spearman rank correlations, and random forest
models. Peak training volume, measured as swimming distance, decreased
significantly during the study period from
32.6±4.8 km/wk to 11.3±8.1 km/wk
(ANOVA, p<0.05); however, body composition showed no significant
changes. Coinciding with the decrease in training volume, the microbial
community structure showed a significant decrease in overall microbial
diversity, a decrease in microbial community structural similarity, and a
decrease in the proportion of the bacterial genera Faecalibacterium and
Coprococcus. Together these data demonstrate a significant
association between short-term changes in training volume and microbial
composition and structure in the gut; future research will establish whether
these changes are associated with energy balance or nutrient intake.
