Saliva alleviates hypertension through enrichment of intestinal Bacteroides thetaiotaomicron

Oral environment is closely linked to blood pressure regulation, yet the underlying mechanisms remain poorly understood. In this study, we demonstrated that saliva, abundantly secreted in the oral cavity, played a critical role in sustaining the abundance of Bacteroides thetaiotaomicron (Bt) in the gut microbiota, contributing to lowering blood pressure. Further investigation revealed that the mechanism driving this process originated from mucins and metal ions in saliva, which work synergistically to promote Bt growth. In turn, the significantly increased gut abundance of Bt contributed to blood pressure downregulation indirectly by synthesizing short-chain fatty acids and regulating sodium ion channels in the gut. Based on these findings, a unique saliva-driven surface-engineered probiotic strain was developed to advance clinical translational potential by boosting in vivo bioavailability, thus improving blood pressure management. This study not only revealed that saliva lowered blood pressure through gut microbiota but also proposes a novel perspective to hypertension management.