Aging and the microbiome: implications for health and disease

The gut microbiota plays a fundamental role in maintaining host homeostasis, and the aging process profoundly influences its composition and function. Accumulating evidence suggests that alterations in the gut microbiota are not just a consequence of aging, but also an active driver of age-related physiological decline. In particular, age-dependent gut microbiota dysbiosis has emerged as a critical factor contributing to host aging and aging-related diseases. This review systematically summarizes alterations in the gut microbiota (e.g., reduced alpha diversity, depletion of beneficial commensals, and enrichment of pathobionts) during the aging process, and discusses the spatiotemporal dynamics and causal relationships between microbial aging and host aging. The regulatory mechanisms by which the gut microbiota influences aging-related diseases, such as metabolic disorders (e.g., obesity, type 2 diabetes, and cardiovascular disease), immunosenescence, and neurodegenerative diseases (e.g., Alzheimer's disease and Parkinson's disease), are also elucidated. Finally, microbiota-targeted intervention strategies (e.g., probiotics, prebiotics, and postbiotics) are explored, together with advanced research strategies. [BMB Reports 2026; 59(1): 40-50].