Exploring the effects of six weeks of resistance training on the fecal microbiome of older adult males

Abstract

ABSTRACT Recent advances in molecular biology have enabled researchers to study the gut microbiome. However, only limited evidence has examined whether resistance training alters the gut microbiome, and no studies in this regard have been performed in an older population. Therefore, the purpose of this study was to determine if 6 weeks of resistance training in older males: i) altered bacterial species suggestive of enhanced gut microbiome diversity, and/or ii) altered taxonomic units associated with gut health chosen a priori through an extensive literature search. Fecal samples were collected prior to and following a 6-week resistance training intervention (2x/week) in 16 older Caucasian males (65±9 years old, 28.1±3.1 kg/m2 ) with minimal prior training experience. After training concluded, DNA was isolated from pre-and post-training fecal samples, and taxa were quantified using sequencing to amplify the variable region 4 (V4) of the 16S ribosomal RNA gene. Training significantly increased whole-body lean/soft tissue mass (determined by dual energy x-ray absorptiometry) as well as leg extensor strength (p<0.05). Markers of microbiome diversity as well as select bacteria chosen for analysis a priori were not significantly altered with training. However, MetaCYC pathway analysis indicated metabolic capacity of the microbiome to produce mucin increased; blood analysis indicated serum Zonulin was significantly decreased after training (p<0.05), further suggesting intestinal barrier integrity was improved. In conclusion, this study adds to the limited literature examining how resistance training affects the gut microbiome. Interestingly, our data suggest that resistance training in older Caucasians may improve intestinal barrier integrity, and warrant further in-depth research in this area.