- Review
Gut aging is characterized by progressive impairment of epithelial renewal, barrier integrity, immune–metabolic homeostasis, and microbial ecology. Fermented foods represent a promising dietary platform for modulating these processes because they provide functional microbes together with fermentation-derived metabolites and matrix components. This review critically evaluates fermented-food-derived and fermented-food-associated functional microbes for healthy gut aging using an evidence-weighted framework that distinguishes direct gut-aging evidence, age-relevant evidence, and mechanistic surrogate evidence. Current findings indicate that microbial interventions may alleviate gut-aging phenotypes by regulating epithelial senescence and intestinal stem-cell homeostasis, attenuating oxidative and inflammatory stress, reinforcing barrier and mucus function, and restoring aging-associated microbial functions. These effects involve microbial and microbiota-mediated effectors, including short-chain fatty acids, tryptophan-derived indoles, bile acid derivatives, exopolysaccharides, and bioactive peptides. Importantly, food matrices influence microbial survival, gastrointestinal delivery, substrate availability, and metabolic activity and therefore constitute an integral determinant of functional efficacy. Emerging multi-omics, artificial intelligence-assisted screening, and targeted delivery technologies may further facilitate the development of functional microbial interventions. However, direct evidence from source-resolved fermented-food strains and naturally aged hosts remains limited. Future studies should integrate microbial provenance, food-matrix context, strain-level functional potential, metabolite output, and aging-specific intestinal endpoints to support evidence-based functional-food strategies for healthy gut aging.
15 November 2026










