Frequency And Mode Of Physical Activity Influence Gut Microbial Composition In Overweight And Obese Adults

Abstract

Chronic diseases are linked to adverse phylogenetic and functional alterations in the gut microbiota. Physical activity (PA) regimens may provide a low-cost and practical means to improve “gut health” in individuals at-risk of developing chronic disease. Endurance exercise has been shown to alter gut microbial composition in heavier sedentary individuals but it is not known how other PA modes impact the gut microbiota. It is hypothesized that PA mode and frequency may underlie differences in the gut microbiota in heavier adults. PURPOSE: To examine the relationship between PA measures and gut microbial richness and evenness and composition in overweight and obese adults. METHODS: Adults (n=38), 28-55 years old with BMI 27-36 kg·m-2 were asked about their frequency of aerobic, strength, and stretching exercise during one week. Participants were measured for their age-predicted VO2 max using a modified Bruce protocol on a treadmill. DNA was extracted from self-collected fecal samples for Illumina MiSeq amplicon sequencing of 16S rRNA V4. Sequencing reads were processed according to MOTHUR standard operating procedures, with operational taxonomic unit assignment at the 97% similarity threshold. General linear models were used to test effect of PA measures on alpha diversity indices. Distance-based redundancy analyses were used to evaluate community composition in relation to PA measures. RESULTS: Shannon and Simpson indices did not differ by estimated VO2 max nor by PA frequency and mode (p > 0.05). Frequency and mode of PA explained more variability in the gut microbial community (11.6%) than estimated VO2 max (1.9%). Community patterns were not explained by estimated VO2 max (ρ = 0.81). However, PA frequency and mode did explain community patterns with the frequency of strength training during the week showing a greater impact (ρ < 0.01) than aerobic (ρ = 0.66) and stretching exercise (ρ = 0.72). CONCLUSIONS: PA frequency and mode exhibit greater impacts on the gut microbial community structure than cardiorespiratory fitness in overweight and obese adults. In particular, the incorporation of strength exercise may have a larger impact on the gut microbial community than previously thought. Supported by Montana State University Research Initiative 51040-MUSRI2015-03 and USDA-NIFA 2017-67018-26367.