Liver–Microbiome Axis in Health and Disease

An intestinal microbiome signature is emerging in various liver diseases independent of disease stage. Microbiota profiles may differ between various liver disease etiologies. Microbiota and microbiota-derived factors have a key role in liver cirrhosis and associated pathologies. Advanced liver disease is characterized by a circulating microbiome. Some commensals prevent liver disease in preclinical studies. The intestinal and hepatobiliary tract exhibits host-specific commensal colonization. The resident microbiota has emerged as a key player in intestinal and hepatic diseases. Alcoholic and nonalcoholic fatty liver diseases (ALD/NAFLD), primary sclerosing cholangitis (PSC), liver cirrhosis, and some of their clinical complications, such as hepatic encephalopathy (HE), have been linked to a microbial signature, as also observed for severe liver inflammation in alcoholic hepatitis. In turn, the liver impacts, and communicates with, the microbiota through hepatic mediators, such as bile acids or inflammatory signals. Therefore, a liver–microbiome bidirectional crosstalk appears to be critical in health and various liver diseases and could be therapeutically targeted, such as by fecal microbiota transplantation. The intestinal and hepatobiliary tract exhibits host-specific commensal colonization. The resident microbiota has emerged as a key player in intestinal and hepatic diseases. Alcoholic and nonalcoholic fatty liver diseases (ALD/NAFLD), primary sclerosing cholangitis (PSC), liver cirrhosis, and some of their clinical complications, such as hepatic encephalopathy (HE), have been linked to a microbial signature, as also observed for severe liver inflammation in alcoholic hepatitis. In turn, the liver impacts, and communicates with, the microbiota through hepatic mediators, such as bile acids or inflammatory signals. Therefore, a liver–microbiome bidirectional crosstalk appears to be critical in health and various liver diseases and could be therapeutically targeted, such as by fecal microbiota transplantation. liver-derived cholesterol derivates that control digestion, and modulate the microbiota and metabolism. a term for lipid accumulation in hepatocytes. a term for late-stage liver disease (irrespective of the underlying pathology) that is characterized by scarring and fibrosis. all the genetic material present in an environmental sample (i.e., host cells plus microorganisms). the entire microbial flora or collection of microbial genes from bacteria, viruses, or fungi in a given environment (e.g., intestine). usually benign endogenous microbes that might turn pathogenic if ecosystem changes. a complication of liver cirrhosis that is characterized by increased pressure in the portal circulation leading to esophageal varices, spleen enlargement, and other signs of advanced liver disease. a chronic disease with characteristic bile duct strictures that damage the liver, eventually culminating in liver cirrhosis.