Fermented Rice Bran: A Promising Therapeutic Agent Against High-Fat Diet-Induced Metabolic Disorders

The increasing consumption of a high-fat diet (HFD) triggers metabolic diseases such as obesity, diabetes, dyslipidemia, and MAFLD (metabolic dysfunction-associated fatty liver diseases). This situation demands natural and healthy therapeutic diets. Rice bran is a widely available, nutrient-dense by-product of rice. This study aimed to explore the compositional profile of optimized solid-phase fermented rice bran (FRB) and nonfermented rice bran (NFRB) and, subsequently, its effect on HFD-induced obese rats. We found that the fermentation process improved the nutritional quality and antioxidant properties of rice bran, and FRB supplementation (8 weeks) decreased body weight gain by 3.5%, blood glucose levels by 2.03 mmol/L, and liver fat. However, FRB administration improved cognitive function, while the improvement in lipid profile was associated with the downregulation of hepatic genes (G6PC, FASN, and HMGCR) expression. Additionally, liver tissue staining suggests that FRB supplementation can improve liver morphology by reducing sinusoidal dilation, fat accumulation, and necrosis. Our results demonstrate that FRB could be effectively used to treat and prevent lifestyle-related diseases.