This study investigates changes in the gut microbiome associated with cirrhosis and its complications. The researchers used multi-tagged pyrosequencing to quantify stool microbiota and calculated the cirrhosis dysbiosis ratio (CDR) to assess the ratio of autochthonous to non-autochthonous taxa. The CDR was highest in healthy controls and decreased in compensated, decompensated, and inpatients with cirrhosis. The microbiome remained stable in stable outpatients but changed after decompensation, particularly after hepatic encephalopathy (HE) development. In a longitudinal cohort of infected cirrhotics, the CDR was significantly lower and endotoxin levels were higher in those who developed death, organ failure, or acute-on-chronic liver failure (ACLF) within 30 days. The study concludes that the gut microbiome in cirrhosis changes with disease progression, remains stable in stable disease courses, and is associated with poor outcomes. The CDR is a useful semi-quantitative measure of dysbiosis in cirrhosis.This study investigates changes in the gut microbiome associated with cirrhosis and its complications. The researchers used multi-tagged pyrosequencing to quantify stool microbiota and calculated the cirrhosis dysbiosis ratio (CDR) to assess the ratio of autochthonous to non-autochthonous taxa. The CDR was highest in healthy controls and decreased in compensated, decompensated, and inpatients with cirrhosis. The microbiome remained stable in stable outpatients but changed after decompensation, particularly after hepatic encephalopathy (HE) development. In a longitudinal cohort of infected cirrhotics, the CDR was significantly lower and endotoxin levels were higher in those who developed death, organ failure, or acute-on-chronic liver failure (ACLF) within 30 days. The study concludes that the gut microbiome in cirrhosis changes with disease progression, remains stable in stable disease courses, and is associated with poor outcomes. The CDR is a useful semi-quantitative measure of dysbiosis in cirrhosis.