Abstract
BACKGROUND: Type 2 diabetes mellitus (T2DM) development is closely linked to microbiota, influenced by geography, ethnicity, gender, and age. While the relationship between oral microbiota and T2DM has been explored, specific microbiota associated with T2DM in the Dai and Han populations remains unclear. This study aims to compare oral microbiota differences and identify keystone species between these populations, both with and without T2DM. METHODS: We recruited 28 han participants (6 healthy children, 10 healthy adults, 12 adults with T2DM) and 34 Dai participants (11 healthy children, 10 healthy adults, 13 adults with T2DM). Blood samples were collected for biochemical analysis, and saliva samples underwent DNA extraction and 16S rRNA sequencing. RESULTS: Age significantly influenced oral microbiota differences between the Dai and Han populations, overshadowing the effects of diabetes. In the Dai population with T2DM, notable increases in Alistipes putredinis, Lactobacillus spp., Faecalibacterium prausnitzii, and Akkermansia muciniphila were observed compared to the Han population. Keystone genera differed, with Fusibacter central to the Dai population's microbial network, while the Han network was more scattered. CONCLUSION: This is the first comparative analysis of oral microbiota in the Dai and Han populations with T2DM, highlighting age and ethnicity's influence on microbial composition.