Can ACTN3 help with gut health?

There is currently no scientific evidence that ACTN3 influences gut health. ACTN3 encodes alpha-actinin-3, a protein expressed only in fast-twitch muscle fibers and associated with sprint and power performance. No published studies link ACTN3 variants to gut microbiota composition, intestinal barrier function, or inflammatory bowel diseases. Evidence from consumer DNA tests on ACTN3 is limited to athletic performance—and even there, effect sizes are small and not predictive. For improving gut health, focus on established factors like fiber intake, probiotics, stress reduction, and medical evaluation. A genetic test for ACTN3 provides no actionable insights for gut health. Claims that ACTN3 can help with gut issues should be regarded as marketing or speculation.