Abstract
Red mold rice, fermented by Monascus spp., has been reported to modulate gut microbiota composition and improve metabolic health. Previous studies indicate that red mold rice can reduce cholesterol, inhibit hepatic lipid accumulation, and enhance bile acid excretion, while also altering gut microbiota under high-fat dietary conditions. However, it remains unclear whether these effects are directly due to Monascus-derived products modulating gut microbiota or are a consequence of improved metabolic health conditions, which indirectly influence gut microbiota. This study aimed to evaluate the effects of Monascus pilosus SWM 008 fermented red mold rice and its components-monascin, monascinol, ankaflavin, and polysaccharides-on gut microbiota and metabolic health in rats fed a normal diet. Over eight weeks, physiological, biochemical, and gut microbiota parameters were assessed. Results showed no significant changes in body weight or liver/kidney function, confirming safety. Gut microbiota analysis revealed that red mold rice, monascin, monascinol, and polysaccharides significantly altered gut microbiota composition by increasing the relative abundance of beneficial bacteria, such as Akkermansia muciniphila, Ligilactobacillus murinus, and Duncaniella dubosii. Functional predictions indicated enhanced vitamin K2 biosynthesis, nucleotide metabolism, and other metabolic pathways linked to improved gut health. In conclusion, Monascus pilosus SWM 008 fermented red mold rice demonstrated safety and beneficial effects, suggesting its potential as a functional food to maintain gut microbiota balance under normal dietary conditions.