Structural characterization of red yeast rice-derived polysaccharide and its promotion of lipid metabolism and gut function in high-fat diet-induced mice

This study explored the structure and biological activities of a novel polysaccharide, PRY1–1, isolated from red yeast rice (RYR) through solid-state fermentation and biotransformation by Monascus purpureus. The structure of PRY1–1 was characterized by Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and other analytical techniques, revealing distinct differences from previously identified mycelial and extracellular polysaccharides. Functional assessments were performed on high-fat diet (HFD)-induced mice to evaluate the impact of PRY1–1 on lipid metabolism and gut function. The results demonstrated that PRY1–1 effectively ameliorated HFD-induced lipid metabolism disorders in the liver and epididymal white adipose tissue (eWAT) by regulating the levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), leptin, adiponectin. Additionally, PRY1–1 protected gut function by enhancing gut barrier integrity, modulating gut microbiota composition, and regulating gut metabolite levels. This study offers new insights into the mechanisms by which RYR polysaccharides influence lipid metabolism, highlighting the potential of PRY1–1 as a functional component with significant health benefits. [Display omitted] •A novel homogeneous polysaccharide, PRY1-1, was purified from RYR through solid-state biotransformation by M. purpureus.•The structure of PRY1-1 was elucidated as →4)-α-D-Glcp-(1→ main chain, α-Manp and β-Galf branch chains.•Functional assessments based on HFD-induced mice demonstrated the potential of PRY1-1 on lipid metabolism and gut function.