Association between oral microbial diversity (only bacteria) and diabetes in U.S. adults: analysis of NHANES 2009–2012 data

A significant association was found between oral microbial diversity and diabetes. According to the completely adjusted model, a one-unit increment in the Shannon-Wiener Index was associated with a 12.1% increase in the likelihood of developing diabetes (OR = 1.121, 95%CI: 1.120 ~ 1.122). Subgroup analyses showed divergent findings. In subgroups with lower body weight and BMI, increased microbial diversity correlated with a decreased likelihood of developing diabetes (OR = 0.68 (0.68-0.68)); Conclusions: Oral microbial diversity exhibits a complex relationship with diabetes risk. The increase and subsequent decrease of oral microbiota diversity in relation to diabetes risk. This suggests that certain specific microbes or interactions between microbes may influence the development of diabetes. However, due to the many limitations of this study, it cannot prove the causal relationship between oral microbial richness and diabetes. Further longitudinal and mechanistic studies are essential to elucidate the causal links and dynamic alterations between the oral microbiome and the progression of diabetes.