The effect of chitosan supplementation on liver function, hepatic steatosis predictors, and metabolic indicators in adults with non-alcoholic fatty liver disease: a randomized, double-blinded, placebo-controlled, clinical trial

Abstract Background Non-alcoholic fatty liver disease (NAFLD) is a disease with high complications. An increment in dietary fiber consumption is an approach to NAFLD management, and chitosan as dietary fiber can play a role in the management of NAFLD. Thus, the present study aimed to investigate the effect of chitosan supplementation on liver function, hepatic steatosis predictors, and metabolic indices in adults with NAFLD. Methods Seventy-two adults with NAFLD were randomly assigned to consume either 1.5 g/day chitosan or placebo along with a low-calorie (− 500 kcal/day) diet for 8 weeks in a parallel, randomized, double-blinded, placebo-controlled, clinical trial. Participants were assessed for dietary intake, physical activity, and anthropometric indices. Blood samples were taken to measure fasting blood sugar (FBS), cholesterol, triglycerides, high- and low-density lipoprotein (HDL and LDL). Liver function indices including alanine aminotransferase (ALT), aspartate transaminase (AST), and gamma-glutamyltransferase (GGT) were evaluated using blood samples as the primary outcomes. Fatty liver index (FLI), hepatic steatosis index (HSI), and triglyceride-glucose index (TyG) were calculated as hepatic steatosis predictors’ indices. Results After 8 weeks of study, 66 participants finished the study. In comparison with placebo, chitosan supplementation reduced weight (P = 0.041), waist circumference (P = 0.049), AST (P = 0.040), ALT (P = 0.001), and GGT (P = 0.028). Although the reduction of FBS, triglycerides, cholesterol, LDL, FLI, HSI, and TyG, and increment in HDL was higher in the chitosan group, the results were not significant (P > 0.05). Conclusions Eight-week supplementation with 1.5 g/day chitosan along with a low-calorie diet could possibly reduce weight, waist circumference, AST, ALT, and GGT, and ameliorate NAFLD. Further investigations are recommended. Trial registration The trial was registered at IRCT.ir as IRCT20140502017522N4 (March 2023).