Fecal Microbiota in Non-Alcoholic Fatty Liver Disease and Non-Alcoholic Steatohepatitis: A Systematic Review

Background: With the increasing prevalence of obesity, non-alcoholic fatty liver disease (NAFLD), has become a frequent cause of chronic liver disease, often leading to cirrhosis. In recent decades, gut microbiota have been evaluated as an effective factor in NAFLD pathogenesis, causing steatohepatitis by involving the host immune system. The aim of this study is to evaluate gut microbiota dysbiosis in NAFLD/NASH patients in comparison to healthy controls. Methods: We conducted a systematic search of published studies that have examined the composition of gut microbiota in relation to NAFLD. PubMed, Scopus and ISI Web of Science were searched. After the exclusion of irrelevant studies, 15 eligible studies were included and summarized. Results: Overall, some studies reported the composition of microbiota at the phyla level, while others reported them at smaller subgroups; the results of studies were contradictory in some cases. Conclusion: Overall, study findings indicate a relationship between microbial composition and NAFLD. Study methods and sequencing techniques influenced these results. Keywords: