Bariatric surgery and non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a chronic disease that may lead to cirrhosis and hepatocellular carcinoma; its close relationship with obesity and the metabolic syndrome involves an increasing prevalence. Invasive liver biopsy is the gold standard diagnosis technique for NAFLD but entails risks. Therefore, transient elastography, a non-invasive technique with high reliability, is frequently used in clinical practice. Bariatric surgery is the only effective treatment for long-term weight loss and obesity-related metabolic conditions improvement. Although studies report encouraging results of bariatric surgery as a valuable therapy for NAFLD, guidelines for its use in NAFLD are ambiguous. Indeed, the mechanisms driving this improvement are largely unknown, but likely involve weight loss-dependent and independent factors including anatomic and hormonal changes. This review aims to update the relationship between NAFLD and bariatric surgery, focusing on the indications for surgery and the mechanisms implied in NAFLD improvement.