The effects of chronic alcohol consumption on the bowel flora and the potential therapeutic role of probiotics in alcohol-induced liver injury have not previously been evaluated. In this study, 66 adult Russian males admitted to a psychiatric hospital with a diagnosis of alcoholic psychosis were enrolled in a prospective, randomized, clinical trial to study the effects of alcohol and probiotics on the bowel flora and alcohol-induced liver injury. Patients were randomized to receive 5 days of Bifidobacterium bifidum and Lactobacillus plantarum 8PA3 versus standard therapy alone (abstinence plus vitamins). Stool cultures and liver enzymes were performed at baseline and again after therapy. Results were compared between groups and with 24 healthy, matched controls who did not consume alcohol. Compared to healthy controls, alcoholic patients had significantly reduced numbers of bifidobacteria (6.3 vs. 7.5logcolony-forming unit [CFU]/g), lactobacilli (3.15 vs. 4.59logCFU/g), and enterococci (4.43 vs. 5.5logCFU/g). The mean baseline alanine aminotransferase (ALT), aspartate aminotransferase (AST), and γ-glutamyl transpeptidase (GGT) activities were significantly elevated in the alcoholic group compared to the healthy control group (AST: 104.1 vs. 29.15U/L; ALT: 50.49 vs. 22.96U/L; GGT 161.5 vs. 51.88U/L), indicating that these patients did have mild alcohol-induced liver injury. After 5 days of probiotic therapy, alcoholic patients had significantly increased numbers of both bifidobacteria (7.9 vs. 6.81logCFU/g) and lactobacilli (4.2 vs. 3.2logCFU/g) compared to the standard therapy arm. Despite similar values at study initiation, patients treated with probiotics had significantly lower AST and ALT activity at the end of treatment than those treated with standard therapy alone (AST: 54.67 vs. 76.43U/L; ALT 36.69 vs. 51.26U/L). In a subgroup of 26 subjects with well-characterized mild alcoholic hepatitis (defined as AST and ALT greater than 30U/L with AST-to-ALT ratio greater than one), probiotic therapy was associated with a significant end of treatment reduction in ALT, AST, GGT, lactate dehydrogenase, and total bilirubin. In this subgroup, there was a significant end of treatment mean ALT reduction in the probiotic arm versus the standard therapy arm. In conclusion, patients with alcohol-induced liver injury have altered bowel flora compared to healthy controls. Short-term oral supplementation with B. bifidum and L. plantarum 8PA3 was associated with restoration of the bowel flora and greater improvement in alcohol-induced liver injury than standard therapy alone.