ABSTRACT
The human gut is populated by a complex community of microbiota that coexists with the host to maintain homeostasis.Macrogenomic and metabonomics analysis shows that the imbalance in gut microbiota composition and diversity, some bacterial components, metabolites and the signaling pathways mediated by them are involved in the occurrence and development of a variety of diseases, especially in the elderly.Intestinal microorganisms are one of the important factors affecting age-related diseases and can provide insights on treatment strategies for the elderly.This review focuses on the composition of the intestinal microbiota, interaction between the microbiota and the host, features of the gut microbiota in common geriatric diseases and pathogenic mechanisms.