Update on the Effect of Probiotics and Prebiotics for the Treatment of Non-alcoholic Fatty Liver Disease: a Systematic Review

Introduction: Non-alcoholic fatty liver disease (NAFLD) is the accumulation of fat vacuoles in liver cells. It can progress to non-alcoholic steatohepatitis (NASH), which could eventually lead to liver cirrhosis and hepatocellular carcinoma. Until now, there is no effective treatment for these conditions, except managing through modifications in lifestyle and diet (including controlling weight). Several studies have tried to establish the effects of various treatments, but unfortunately the results have been disappointing so far. Prebiotics and probiotics have been shown to improve hepatic steatosis and steatohepatitis through their modulatory effect on the immune system. Objective: The objective of this review is to assess the effectiveness of probiotics and prebiotics in the treatment of NAFLD and NASH. Materials & Methods: A systematic search of relevant literature was conducted on PubMed, the Cochrane Library, Science Direct and MEDLINE databases (for the period 1990 to 2014) using the keywords mentioned below. Results: These include several observations – various prebiotic/probiotic combinations used in different randomized control trials (RCTs) and non-RCTs indicating signs of histological and radiological improvement, a decrease in ALT and AST, and an improvement in lipid profile and insulin resistance – that could justify the use of this therapy on NAFLD/NASH patients. Conclusion: Research in this domain is constantly being updated due to the continuous accumulation of vast data. However, there is need for specifying the type, dose and duration of the probiotic/prebiotic used, and evaluation of its clear impact on the general condition of the patient. Therefore, large-scale RCTs are needed to provide evidence for the generalization of the treatment.