Investigation of oral microbiome composition in elderly Chinese patients with hypertension: a cross-sectional study

Background: Hypertension is a prevalent metabolic disorder in the elderly, with its pathogenesis linked to gut microbiota dysbiosis. Recent studies suggested that oral microbiota may also play a role in hypertension development, yet its relationship with hypertension in the elderly remains underexplored. Objective: This cross-sectional study aimed to examine the structure of the oral microbiota and its association with hypertension in elderly patients, providing insights into hypertension prevention and treatment. Methods: A total of 206 subjects (60-89 years) were categorized into normal (CON) and hypertensive (HTN) groups, based on the Chinese Hypertension Guidelines. Saliva samples were analyzed using 16S rRNA gene sequencing. Results: Oral microbiota composition was significantly influenced by blood pressure. At the phylum level, Synergistetes and Spirochaetes were more significantly abundant in the HTN group, while at the genus level Treponema and Leptothrix was higher, Actinomyces and Capnocytophaga were lower in HTN. Random Forest analysis identified 15 key microbiota as strong discriminators of HTN (AUC 0.74). Blood pressure was negatively correlated with Actinomycetes and positively correlated with Leptothrix. PICRUST2 analysis revealed elevated chlorinated compound degradation in HTN patients. Conclusions: This study identified distinct oral microbiota in elderly hypertensive patients, highlighting the role of the oral microbiome in hypertension pathogenesis.