Aparicio Mera, RaquelManzano Carrasco, SamuelHernández Martín de San Pablo, AntonioCuevas, RicardoGarcía Unanue, Jorge Fernando2026-07-302026-07-302026Aparicio-Mera, R., Manzano-Carrasco, S., Hernandez-Martin, A., Cuevas, R., & Garcia-Unanue, J. (2026). The interplay of physical activity, psychological stress, and gut microbiota in adults: a systematic review. Sports Medicine and Health Science.2097-62912666-3376https://hdl.handle.net/11268/17341Aging 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. 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.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Medicina, Salud y DeportesEjercicio FísicoEstrés PsicológicoMicrobioma Gastrointestinaljournal article10.1016/j.smhs.2026.07.004open accessCiencias médicasDeporteMicrobiologíaGoal 3: Ensure healthy lives and promote well-being for all at all ages