Camu-camu decreases steatosis and markers of liver injury (Shotgun sequencing).
Non-alcoholic fatty liver disease (NAFLD) affects approximately 25% of the adult population, making it the most prevalent liver disease worldwide. As of today, no effective drug treatments against NAFLD are available. Previous animal studies reported that a polyphenol-rich extract from the Amazonian berry camu-camu (CC) prevented hepatic steatosis in a mouse model of diet-induced obesity in association with changes in gut microbiota composition, but no clinical trial has investigated whether CC has beneficial effects on these parameters.  Objective: The primary outcome of this study was to determine the impact of CC on hepatic steatosis and the exploratory outcomes were to evaluate changes in metabolic and gut microbiota profiles following CC supplementation.  Methods: A randomized, double-blind, placebo-controlled crossover trial was con-ducted on 30 adults with overweight and hypertriglyceridemia. Participants were instructed to consume daily 1.5 g of CC capsules or maltodextrin (placebo) for 12 weeks. Metabolic phenotypes (anthropometric measurements, blood profiles, and indices of glucose homeostasis) and fecal microbiota composition were assessed before and after each intervention phase.  Results: CC treatment was found to decrease liver fat (%HFF) by 7.43% as com-pared to baseline, as measured by magnetic resonance imaging. Liver fat in-creased by 8.42% from baseline during the placebo intervention, corresponding to a significant difference of 15.85% (P=0.003) in relative liver fat change between the CC and placebo arms. Moreover, CC significantly (P<0.05) decreased circu-lating levels of aspartate (AST) and alanine aminotransferases (ALT), which are markers of liver injury. When comparing the fecal microbiota composition at base-line and post-supplementation, we found that CC promoted taxonomic and func-tional changes in the gut microbiota, as revealed by both 16S-rRNA and meta-genomic analyses..  Conclusion: This is the first human clinical trial to report that CC supplementation decreases hepatic steatosis and plasma AST and ALT levels in subjects with over-weight and hypertriglyceridemia. These changes were associated with a shift in  the gut microbiota composition and function. These studies support that polyphe-nol-rich prebiotic supplements may be used to reduce liver fat in overweight adults thus reducing the risk to develop NAFLD.