Hepatoprotective Effect of Probiotic Lactic Acid Bacteria on Thioacetamide-Induced Liver Fibrosis in Rats

Hepatic fibrosis is a reversible wound-healing response characterized by the accumulation of extracellular matrix. Probiotics have been used to prevent and treat various disorders. The aim of the present study was to investigate the hepatoprotective effects of probiotic lactic acid bacteria (mixture ofLactobacillus paracasei,Lactobacillus casei, andWeissella confusa) on thioacetamide (TAA)-induced liver fibrosis in rats. Thirty-five male Wistar rats were randomly divided into five groups: (1) control, (2) TAA, (3) TAA+probiotics, (4) TAA+silymarin, and (5) probiotics. Group 1 rats received a standard diet. In groups 2-4, fibrosis was induced by intraperitoneal injection of TAA (200 mg/kg BW) 3 times weekly for 8 consecutive weeks. Group 4 received TAA plus 100 mg/kg BW of silymarin 2 times weekly. Groups 3 and 5 were fed 10(9) CFU/mL viable microbial cells daily by gavage. The rats were sacrificed after 8 weeks of treatment. Liver tissues were collected immediately and processed for histopathological, lipid peroxidation, and Western blot analyses of TNF-alpha, TGF-beta 1, and alpha-SMA. Blood serum was collected to measure liver enzymes. Rats in the TAA groups suffered from hepatic injury (increased serum enzyme levels, liver inflammation, and increased concentration of TNF-alpha, TGF-beta 1, and alpha-SMA proteins) and extensive liver fibrosis. In contrast, TAA-treated rats receiving probiotics or silymarin had significantly lower serum enzyme levels, less inflammation, and less fibrosis. Liver damage was lower in the TAA+probiotics-treated group. Consumption of a mixture of probiotic lactic acid bacteria attenuates the development of liver fibrosis.