Attributes of Physical Activity and Gut Microbiome in Adults: A Systematic Review

Growing evidence shows the contribution of physical activity interventions to the gut microbiome. However, specific physical activity characteristics that can modify the gut microbiome are unknown. This review's aim was to explore the contribution of physical activity intervention characteristics on human gut microbiome composition, in terms of diversity, specific bacterial groups, and associated gut microbiome metabolites. A literature search in PubMed; Cochrane Library; CINAHL-EBSCO; SCOPUS; Web of Science; ClinicalTrials.gov; PROSPERO; and ProQuest. Five studies met the inclusion criteria of a physical activity intervention duration of at least five weeks, with any description of the type or dose used. All included studies reported an endurance training; two studies used endurance and an additional muscle-strengthening training regimen. All studies reported using a dietary intervention control. Reported gut microbiome α-diversity changes were non-significant, β-diversity changes were mixed (three studies reported an increase, two reported non-significant changes). All studies reported significant changes in the abundances of specific bacterial/archaea groups and bacteria-related metabolites following interventions. In conclusion, physical activity (regardless of specific characteristics) has significant contribution to gut microbiome composition and associated metabolites. There are no current recommendations for physical activity to promote gut microbiome composition. Future studies should focus on the contribution of current recommended physical activity dose to gut microbiome composition.