Microbiota transplants from feces or gut content attenuated portal hypertension and portosystemic collaterals in cirrhotic rats

Liver cirrhosis and portal hypertension is the end of chronic liver injury with hepatic, splanchnic and portosystemic collateral systems dysregulation. Liver injury is accompanied by gut dysbiosis whereas dysbiosis induces liver fibrosis, splanchnic angiogenesis and dysregulated vascular tones vice versa, making portal hypertension aggravated. It has been proved that intestinal microbiota transplantation alleviates dysbiosis. Nevertheless, the influences of microbiota transplantation on cirrhosis-related portal hypertension are not so clear. Liver cirrhosis with portal hypertension was induced by bile duct ligation (BDL) in rats. Sham rats were surgical controls. Rats randomly received vehicle, fecal or gut (terminal ileum) material transplantation. The results showed that microbiota transplantation from feces or gut material significantly reduced portal pressure in cirrhotic rats (P=0.010, 0.044). Hepatic resistance, vascular contractility, fibrosis and relevant protein expressions were not significantly different among cirrhotic rats. However, microbiota transplantation ameliorated splanchnic hyperdynamic flow and vasodilatation. Mesenteric angiogenesis, defined by whole mesenteric window vascular density, decreased in both transplantation groups and phosphorylated endothelial nitric-oxide synthase (eNOS) was down-regulated. Portosystemic shunts determined by splenorenal shunt (SRS) flow decreased in both transplantation groups (P=0.037, 0.032). Shunting severity assessed by microsphere distribution method showed consistent results. Compared with sham rats, cirrhotic rats lacked Lachnospiraceae. Both microbiota transplants increased Bifidobacterium. In conclusion, microbiota transplantation in cirrhotic rats reduced portal pressure, alleviated splanchnic hyperdynamic circulation and portosystemic shunts. The main beneficial effects may be focused on portosystemic collaterals-related events, such as hepatic encephalopathy and gastroesophageal variceal hemorrhage. Further clinical investigations are mandatory.