BACKGROUND: Alcoholic liver disease is the leading cause of cirrhosis worldwide. Due to an increase in alcohol overuse, alcoholic liver disease has become an increased burden on health care systems. Abstinence from alcohol remains the cornerstone of alcoholic liver disease treatment; however, this approach is hampered by frequent relapse and lack of specific therapy for treating advanced cases of liver disease. In the present study, we hypothesized that gut microbiota drive the development of liver fibrosis and that modulation of gut microbiota with the gut-selective, nonabsorbable antibiotic rifaximin attenuates alcoholic liver fibrosis.

METHODS/DESIGN: Our double-blind, placebo-controlled trial will include 136 participants with biopsy-verified alcoholic fibrosis (Ishak liver fibrosis score of 1-4). Participants are randomized 1:1 to receive placebo or 550 mg of rifaximin twice daily for 18 months. A liver biopsy will be performed at the end of the treatment period to evaluate the effect of drug treatment on liver fibrosis. Stool, urine, and saliva specimens will be collected before treatment begins, at 1 month, and at the end of the treatment period. Fecal samples are used for microbiome deep sequencing. Changes in microbiome composition are compared before and after the trial medication period and linked to changes in liver fibrosis.

DISCUSSION: This is the first clinical trial to evaluate the effect of gut microbiota on liver fibrosis in humans. If gut microbiota are an important promoter of alcoholic liver disease, current results may open new therapeutic avenues and revolutionize the current understanding of chronic liver diseases.

TRIAL REGISTRATION: EudraCT, 2014-001856-51 . Registered on 16 August 2014.