Polysaccharide peptides from Ganoderma lucidum ameliorate lipid metabolic disorders and gut microbiota dysbiosis in high-fat diet-fed rats

This study aimed to investigate the effects of polysaccharide peptides from Ganoderma lucidum (GLPP) on hyperlipidaemia and gut microbiota dysbiosis in high-fat diet (HFD)-exacerbated hypercholesterolemic rats. Results showed that oral administrations of GLPP markedly alleviated the dyslipidaemia through decreasing the serum levels of triglyceride (TG), cholesterol (TC), free fatty acids (FFA) and low-density lipoprotein cholesterol (LDL-C), and significantly suppressing hepatic lipid accumulation and steatosis. Metagenomic analysis revealed that GLPP supplementation produced significant structure changes on the intestinal microbiota in HFD-fed rats, in particular modulating the relative abundance of functionally relevant microbial phylotypes compared with the HFD group. The Spearman's correlation analysis revealed that the serum and hepatic lipid profiles were negatively correlated with Jeotgalicoccus, Ignavigranum, Sporosarcina, Bacteroides, Anaerovorax, Parasutterella, Alistipes and Alloprevotella, but positively correlated with Allobaculum, Phascolarctobacterium, Psychrobacter, Enterorhabdus, Blautia and Roseburia. Meanwhile, the GLPP treatment regulated the mRNA expression responsible for hepatic lipid metabolism and promoted fecal excretion of total bile acids (BAs). These findings indicated that GLPP ameliorate lipid metabolic disorders through modulating gut microbiota structure and regulating the genes involved in hepatic lipid and cholesterol metabolism.