Exercise is associated with altered gut microbial composition, but studies have not investigated whether the gut microbiota and associated metabolites are modulated by exercise training in humans. We explored the impact of 6 wk of endurance exercise on the composition, functional capacity, and metabolic output of the gut microbiota in lean and obese adults with multiple-day dietary controls before outcome variable collection.
Thirty-two lean (n = 18 [9 female]) and obese (n = 14 [11 female]), previously sedentary subjects participated in 6 wk of supervised, endurance-based exercise training (3 d·wk−1) that progressed from 30 to 60 min·d−1 and from moderate (60% of HR reserve) to vigorous intensity (75% HR reserve). Subsequently, participants returned to a sedentary lifestyle activity for a 6-wk washout period. Fecal samples were collected before and after 6 wk of exercise, as well as after the sedentary washout period, with 3-d dietary controls in place before each collection.
β-diversity analysis revealed that exercise-induced alterations of the gut microbiota were dependent on obesity status. Exercise increased fecal concentrations of short-chain fatty acids in lean, but not obese, participants. Exercise-induced shifts in metabolic output of the microbiota paralleled changes in bacterial genes and taxa capable of short-chain fatty acid production. Lastly, exercise-induced changes in the microbiota were largely reversed once exercise training ceased.
These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent of diet and contingent on the sustainment of exercise.
1Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL; 2Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL; 3Department of Human Performance and Leisure Studies, North Carolina A&T State University, Greensboro, NC; 4Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL; 5Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL
Address for correspondence: Jeffrey A. Woods, Ph.D., 906S, Goodwin Ave., 348 Louise Freer Hall, University of Illinois at Urbana-Champaign, Urbana, IL 61801; E-mail: Woods1@illinois.edu.
Submitted for publication October 2017.
Accepted for publication November 2017.
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