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

Intestinal microbiota affects human health and aging. The composition of intestinal microbiota and inflammation indices in elderly Chinese, especially centenarians, is unclear.

This study aimed to explore the relationships between intestinal microbiota and inflammation in healthy housebound elders in Shanghai, China.

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.

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.

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.