Unveiling the Link Between Oral Microbiome Diversity and Biological Ageing: A Cross‐Sectional Study

AIM: To investigate the relationship between oral microbiome diversity and biological ageing acceleration in a nationally representative U.S. METHODS: Data from 7716 participants in NHANES (2009-2012) were analysed. Oral microbiome diversity was assessed, and biological ageing acceleration was calculated using a validated algorithm. Generalised linear models, restricted cubic splines and smooth curve fitting were applied to evaluate associations. RESULTS: Higher α-diversity of the oral microbiome was significantly negatively correlated with biological ageing acceleration. Stratified analyses revealed that this protective effect was particularly pronounced in men and individuals with hypertension and diabetes. β-Diversity analysis showed significant differences in the association between microbial community composition and biological ageing acceleration, with immune functions potentially modulating these effects. Furthermore, key intervals of α-diversity were identified, which may serve as potential targets for future research on delaying ageing. CONCLUSIONS: In the general U.S. population, greater oral microbiome diversity was associated with lower biological ageing acceleration, especially among men and those with hypertension and diabetes. This association was also observed in Mexican and Hispanic populations.