Gut microbiome drives glycodeoxycholic acid-mediated attenuation of hypertension

Gut microbiota and bile acids are increasingly recognized to regulate blood pressure, but the mechanisms remain unclear. Takeda G-protein coupled receptor 5 (TGR5) is a major receptor for secondary bile acids. We hypothesized that loss of TGR5 function remodels gut microbiota and influences blood pressure. Using CRISPR/Cas9, TGR5 knockout (Tgr5KO) rats on the Dahl Salt-Sensitive (S) background were generated and characterized. Compared to the control S rats, Tgr5KO rats demonstrated significantly lower blood pressure, a distinct shift in gut microbiota composition, and an increase in the secondary bile acid, particularly, glycodeoxycholic acid. Supplementation of glycodeoxycholic acid to the control S rats produced a similar gut microbial shift and lowered blood pressure. Furthermore, cecal microbiota transplantation from Tgr5KO to control S rats lowered blood pressure in the recipient rats. This first loss-of-function study demonstrates that deletion of TGR5 remodels gut microbiota, increases glycodeoxycholic acid, and lowers blood pressure regardless of TGR5 signaling status, identifying a promising gut-liver axis target for lowering hypertension.