Potential Effects of Functional Foods and Dietary Supplements on Metabolic-Associated Fatty Liver Disease and the Underlying Mechanisms: A Narrative Review with a Focus on the Modulation of the Gut Microbiota

Metabolic-associated fatty liver disease (MAFLD) has become the most common liver disease, affecting more than 25% of the adult population worldwide. Functional foods, dietary supplements, and dietary patterns are considered effective measures for treating MAFLD; however, their mechanisms remain unclear. Recent investigations have proven that the gut microbiota is a pivotal regulatory node in MAFLD pathogenesis, with dietary interventions targeting the gut-liver axis showing promising therapeutic potential. This review summarizes the relationships among the gut microbiota, its metabolites, and MAFLD, as well as the effects of functional foods, dietary supplements, and dietary patterns that target the gut microbiota on MAFLD. These interventions maintain gut microbiota homeostasis, modulate the levels of gut metabolites, and regulate physiological pathways such as hepatic lipid accumulation and inflammation, thereby affecting the development of MAFLD. This review provides new insights into the mechanisms of dietary interventions and a novel therapeutic strategy for patients with MAFLD.