The interplay of physical activity, psychological stress, and gut microbiota in adults: a systematic review

Aging is associated with alterations in gut microbiota composition and diversity, which may influence physical, psychological, and metabolic health. Physical activity and psychological stress are key modulators of the gut–brain–body axis. However, the combined and independent effects on the gut microbiota remain unclear. This systematic review was conducted in accordance with PRISMA guidelines (PROSPERO CRD42024608619) and synthesizes evidence from 16 human studies examining associations between physical activity, psychological stress, and gut microbiota composition and diversity. Overall, moderate physical activity was consistently associated with beneficial microbial profiles, including an increased abundance of Akkermansia , Faecalibacterium prausnitzii , Lachnospiraceae/Ruminococcaceae , and Bifidobacterium . In contrast, high-intensity or prolonged exercise was associated with less favorable microbiota patterns, including dysbiosis. Psychological stress is associated with altered microbial composition, including increased Escherichia , Shigella , Parabacteroides , and Blautia . Furthermore, probiotic and symbiotic interventions, particularly strain-specific formulations, have been associated with improvements in perceived stress, psychological well-being, sleep quality, and microbial balance. Multifactorial interventions combining physical activity, diet, and stress management have shown broader benefits, although their individual effects cannot be isolated. Only one multifactorial study simultaneously addressed physical activity and stress-related factors, highlighting the limited evidence regarding their combined effects on gut microbiota outcomes. Overall, these findings suggest that lifestyle-based strategies may support gut microbiota health, although the heterogeneity and study limitations warrant cautious interpretation.