Objective To explore the difference in gut microbiota composition and microbial metabolites between hypertensive and normotensive participants.

Methods From March 2017 to June 2018, 77 patients who were free of coronary heart disease and admitted in the Cardiology Department of Zhongshan Hospital, Fudan University were recruited. According to participants' blood pressure levels, they were categorized into the normotensive group (n=22) and the hypertensive group (n=55). Stool and blood samples from each participant were collected. Our study profiled the microbial community through shotgun metagenomic sequencing and measured fecal short-chain fatty acids and circulating metabolites from choline pathway using targeted metabolomics technology.

Results Significantly higher alpha diversity was observed in the normotensive participants compared with the hypertensive participants. However, their beta diversity was not statistically significant different from each other. At the species level, the relative abundance of fourteen bacteria (e.g., Megamonas funiformis and Clostridium ramosum) was differential between the two groups. Per standard deviation increase in a composite microbiota score, which was constructed on these 14 differential species, was associated with 76% lower odds of hypertension. Besides, circulating levels of trimethylamine N-oxide-related metabolites and fecal levels of short-chain fatty acids were not significantly different between the two groups. Correlation analysis of differential bacteria and metabolites showed that Parasutterella excrementihominis was positively associated with trimethylamine N-oxide and inversely associated with short-chain fatty acids.

Conclusion Gut microbiota disturbance was observed in the hypertensive population. Our results may provide new clues for further studies on hypertension and gut microbiota and offer new prospects for treating and preventing hypertension.