This review examines how exercise remodels the gut microbiome — including compositional shifts and metabolic adaptations — and how exercise-responsive microbial metabolites (short-chain fatty acids, secondary bile acids, formate) regulate immune function across systemic inflammation, antitumor CD8 T-cell immunity, autoimmunity, and metabolic disease.
Emerging evidence supports a causal link between exercise-induced microbiome changes and immune modulation, with specific microbial metabolites identified as candidate mediators of disease protection; however, causal taxa and host-sensing mechanisms remain incompletely defined.
As a narrative review, no primary data are generated; causality between specific microbial taxa and immune outcomes is not firmly established, and the translation of findings into clinical exercise or microbiome-based prescriptions is speculative at this stage.
Clinicians should be aware that exercise may confer immune benefits partly through microbiome remodeling, but microbiome-informed exercise prescriptions and metabolite- or probiotic-based therapies are not yet ready for routine practice pending causal mechanistic studies.
