Aerobic Exercise Training Alters Gastrointestinal Microbiota In Het3 Mice

PURPOSE: We aimed to characterize aerobic exercise training (ET)-induced changes in the gutmicrobiome of a heterozygous aging mouse model (HET3) and determine the relationshipbetween bacterial changes and changes (pre/post) in body composition (body weight, lean and fatmass) and exercise capacity (total work (Joules), distance, and duration). METHODS: HET3 male mice were randomly assigned to a sedentary (SED, N = 16) controlgroup or ET (N = 17) group that trained 5 days/week for 4 weeks at 65% of max work output.Body composition and exercise capacity were assessed pre- and post-ET. Fecal samples werecollected post-ET. 16 s sequencing was performed on a subset of mice (SED, N = 13; ET, N = 13).Using QIIME2, the taxonomy of each amplicon sequence variant (ASV) was assigned using theclassifier generated from the Silva 138.116S rRNA bacteria database. Alpha and beta diversityanalyses were performed in R. Spearman’s correlation analysis was used to examine therelationships between the aggregated phylum-level relative abundances and the changes in bodycomposition and exercise capacity. RESULTS: ET mice exhibit a broader range of alpha diversity with a higher median richness than SED mice (Table 1). Beta diversity analysis revealed a significant separation between the two groups, indicating distinct microbial community compositions. SED mice exhibited a higher abundanceof the Firmicutes phyla, while Bacteroidota was higher in ET mice. The correlation analysis didnot reveal any noteworthy associations between the aggregated phylum-level relative abundancesand the absolute pre-post differences in body composition and exercise capacity indices. CONCLUSIONS: Despite the heterogeneity of HET3 mice, our data suggests that ET leads todistinct gut microbiota changes, contributing to greater microbial diversity in mice. Future workaims to identify the contribution of these changes to biological aging in response to exercise inhumans. TABLE 1 - Alpha diversity values reports as mean ± standard deviation Alpha diversity Observed Chao1 Shannon SED 203.07 ±24.69 203.76 ±25.04 3.948 ±0.412 ET 219.69 ±40.04 221.03 ±40.57 4.10 ±0.290 Kruskal-Wallis Rank P= 0.653 P= 0.653 P = 0.653 Wilcoxon Rank Sum P= 0.684 P=0.684 P= 0.684 Beta Diversity R2 Permutations P.adjusted PERMANOVA 0.16532 999 0.001 ANOSIM 0.46798 999 0.001 Supported by: San Antonio Nathan Shock Center New Investigator Award Funding