Abstract
This study aimed to investigate the differences in gut microbiota diversity and compositional characteristics between long-lived individuals (≥90 years) and individuals at different life stages (children, young and middle-aged adults, and elderly), in order to provide a foundational basis for microbial interventions in healthy aging. An observational cohort design was adopted, recruiting healthy participants divided into 4 age groups: children, young and middle-aged adults, elderly, and long-lived individuals. Fecal samples were collected and subjected to high-throughput 16S rRNA gene sequencing. The alpha diversity, beta diversity, and community structural differences of the gut microbiota were assessed, and representative microbial taxa were identified using LEfSe analysis. The long-lived group exhibited significantly higher species richness and diversity (Chao1 and Shannon indices, P < .05), with a more balanced and stable microbial structure. At the phylum level, the long-lived group had the highest relative abundance of Firmicutes and the lowest of Bacteroidetes. At the genus level, lactic acid bacteria such as Lactobacillus were significantly enriched. LEfSe analysis indicated that lactic acid bacteria-related taxa may serve as characteristic markers of this population. The gut microbiota of long-lived individuals exhibits higher ecological stability and a distinctive composition, which may be associated with healthy aging. These findings provide preliminary evidence for the relationship between longevity and gut microbial ecology and suggest that structural characteristics of these microbial communities may be involved in the process of healthy aging, offering a basis for future exploration of microbial intervention strategies.