Longevity & AgingGut Microbe Metabolites Steer Immune Aging and Could Become Precision Longevity Targets
Aging reshapes the gut microbiome, and with it the chemicals microbes make. This review explains how shifts in short-chain fatty acids, bile acids, tryptophan metabolites, TMAO, amino acid byproducts, vitamins and polyphenol derivatives affect immune cells, weaken the gut barrier and fuel chronic low-grade inflammation (inflammaging). Protective metabolites such as butyrate and indoles decline with age, while pro-inflammatory ones such as TMAO and kynurenine tend to rise. The authors link these changes to liver, fat, muscle and brain disease, and discuss metabolite-based therapies and AI-driven multi-omics as routes to personalized interventions. Much of the evidence comes from mouse studies, and human causal proof is still limited.
