Age-Related Changes in the Composition of Intestinal Microbiota in Elderly Chinese Individuals

Introduction: Intestinal microbiota affects human health and aging. The composition of intestinal microbiota and inflammation indices in elderly Chinese, especially centenarians, is unclear. Objective: This study aimed to explore the relationships between intestinal microbiota and inflammation in healthy housebound elders in Shanghai, China. Methods: We enrolled 156 differently aged adults and assigned them into 4 groups: those aged 35–64 years were assigned into Group AD; 65–79 years into Group YO; 80–94 years into Group MO; and 95–102 years into Group VO. Results: The diversity of intestinal microbiota in Group VO was significantly reduced compared with that of the other 3 groups. Bacteroidetes abundance in Group VO was significantly lower than that in Groups AD, YO, or MO; Proteobacteria abundance showed the opposite trend. Akkermansia, Bifidobacterium, and Lactobacillus abundance in Group VO was significantly higher than that in the other 3 groups; Anaerostipes, Butyricicoccus, and Faecalibacterium abundance showed the opposite trend. Solobacterium abundance in Group VO was significantly lower than that in the other 3 groups; Campylobacter, Porphyromonas, Escherichia, and Pseudomonas abundance showed the opposite trend. Plasma levels of tumor necrosis factor-α (TNF-α), IL-6, and IL-8 in Group VO were significantly higher than those in Groups AD, YO, and MO, while those in Group MO were significantly higher than those in Groups AD and YO. IL-1β and IL-10 plasma levels were not significantly different among the 4 groups. Proteobacteria abundance was positively correlated with TNF-α and IL-8 levels, while Campylobacter abundance was positively correlated with those of TNF-α and IL-6. Anaerostipes and Faecalibacterium abundance was negatively correlated with TNF-α and IL-6 levels. Conclusions: The diversity of intestinal microbiota in the oldest participants (centenarians) decreased significantly, with several beneficial bacterial strains showing increased or decreased abundance; harmful bacterial species showed a similar trend. Our oldest participants (centenarians) demonstrated significantly increased levels of pro-inflammatory cytokines, which may be related to inflammaging.