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

<b><i>Introduction:</i></b> Intestinal microbiota affects human health and aging. The composition of intestinal microbiota and inflammation indices in elderly Chinese, especially centenarians, is unclear. <b><i>Objective:</i></b> This study aimed to explore the relationships between intestinal microbiota and inflammation in healthy housebound elders in Shanghai, China. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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; <i>Proteobacteria</i> abundance showed the opposite trend. <i>Akkermansia</i>, <i>Bifidobacterium,</i> and <i>Lactobacillus</i> abundance in Group VO was significantly higher than that in the other 3 groups; <i>Anaerostipes</i>, <i>Butyricicoccus,</i> and <i>Faecalibacterium</i> abundance showed the opposite trend. <i>Solobacterium</i> abundance in Group VO was significantly lower than that in the other 3 groups; <i>Campylobacter</i>, <i>Porphyromonas</i>, <i>Escherichia</i>, and <i>Pseudomonas</i> 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. <i>Proteobacteria</i> abundance was positively correlated with TNF-α and IL-8 levels, while <i>Campylobacter</i> abundance was positively correlated with those of TNF-α and IL-6. <i>Anaerostipes</i> and <i>Faecalibacterium</i> abundance was negatively correlated with TNF-α and IL-6 levels. <b><i>Conclusions:</i></b> 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.