# Oral microbiome diversity and all-cause mortality in hypertensive adults: findings from a nationally representative cohort

## TL;DR

Higher oral microbiome diversity is linked to lower all-cause mortality in people with hypertension, with possible differences between men and women.

## Contribution

This study identifies oral microbiome diversity as a protective factor against mortality in hypertensive individuals.

## Key findings

- Higher oral microbiome diversity was associated with reduced all-cause mortality risk.
- The Simpson and Shannon–Weiner diversity indices showed significant protective effects.
- Sex may influence the relationship between oral microbiome diversity and mortality risk.

## Abstract

Oral microbiome diversity has been associated with general health. However, its association with long-term outcomes in hypertensive individuals remains unclear.

This study aimed to investigate whether oral microbiome diversity is associated with all-cause mortality in hypertensive individuals.

Data from 2,669 hypertensive individuals in the National Health and Nutrition Examination Survey (NHANES, 2009–2012) were analyzed. Oral microbiome diversity was assessed using four alpha-diversity metrics: the Simpson index, Shannon–Weiner index, Faith’s Phylogenetic Diversity, and observed amplicon sequence variants (ASVs). Weighted multivariable Cox proportional hazards regression and interaction analyses were conducted.

During a mean follow-up of 8.61 years, 268 all-cause deaths occurred. Higher oral microbiome diversity assessed by the Simpson index (hazard ratio [HR] = 0.38; 95% confidence interval [CI], 0.20–0.75; Ptrend < 0.01) and Shannon–Weiner index (HR = 0.47; 95% CI, 0.25–0.88; Ptrend < 0.05), was significantly associated with reduction in all-cause mortality risk. A potential interaction between sex and oral microbiome diversity on mortality risk was observed.

Higher oral microbiome diversity is an independent protective factor for survival in patients with hypertension, with potential sex-specific differences in this association. These findings suggest that enhancing oral microbiome diversity may potentially help promote overall health in individuals with hypertension.