Probiotics and synbiotics may improve liver aminotransferases levels in non-alcoholic fatty liver disease patients.

Non-alcoholic fatty liver disease (NAFLD) is defined as a spectrum of liver diseases ranging from simple steatosis to steatohepatitis (NASH). Alterations in intestinal microbiota and inflammatory response may play a key role in disease progression and development of complications in liver diseases, mainly in cirrhosis and NASH. The aim of this study was to perform a systematic review on randomized clinical trials (RCTs) testing probiotics, prebiotics or both (synbiotics) in the treatment of NAFLD in adult patients. After the screening process, 9 full-text articles were included in the review and 6 studies were excluded. Three randomized controlled trials were finally included in the qualitative synthesis. All patients in all the 3 studies were randomized to receive different formulations of probiotics, synbiotics or placebo. Reductions in aminotransferases were observed in the treated group in 2 of the studies. However, in one study reductions were also detected in the control group. In conclusion, the available evidence precludes, for the moment, recommendations on the use of pre and probiotics in clinical practice.