(P20-055-23) Effects of Aerobic Exercise Training on Age-Related Dysbiosis in HET3 Male Mice

Objectives: The gastrointestinal microbiome is a complex collection of thousands of microorganisms, including bacteria. Aging contributes to alterations in gut microbiota composition and leads to dysbiosis, or a disturbance in the bacterial population, which is associated with adverse health outcomes. Limited research suggests that aerobic exercise is an effective modality for ameliorating microbiota dysbiosis in older individuals; however, specific taxa have not been consistently identified. Thus, this work aims to identify specific bacterial taxa that respond to an aerobic exercise intervention in an aging mouse model.

Methods: Suggested by the National Institute of Aging Interventions Testing Program (ITP) as the most appropriate mouse model for aging studies, HET3 male mice were randomly assigned to exercise training (ET, N=23) or sedentary (SED, N= 20) groups. The ET group mice were trained 5 days/week for 4-weeks at 65% of their maximum work output. At sacrifice, fecal samples were collected. Following DNA isolation, the FASTQ files containing the READS from the amplified 16S gene for 27 samples for the ET and SED mice were mapped against 3.1 million bacterial 16S genes.

Results: Mean change in exercise work was significantly higher (p = 0.0003) in ET (483.3 ± 48.8 J) versus SED mice (194.7 ± 52.0 J) and was positively correlated with reduced body weight (-9.5 ± 1.8 grams, p = 0.01) in the ET mice. After 16S gene mapping, statistically significant differential two-fold (or higher) gene expressions were identified for 33 individual bacterial species. Of the 33 bacterial species,19 bacterial 16S genes were over-expressed, and 12 were under-expressed in the ET versus SED mice. The Firmicutes domain was the prominent example in both groups, in which Clostridia Phylum (Clostridiales class) was upregulated, and phylum Bacilli (Bacillales class) was downregulated.

Conclusions: Aerobic training significantly impacted gut microbiota in HET3 mice. Ongoing studies seek to determine interactions among bacterial species, endurance trainability, and body composition.

Funding Sources: San Antonio Nathan Shock Center New Investigator Award Funding