Study on the Mechanism of Ganoderma lucidum Polysaccharides for Ameliorating Dyslipidemia via Regulating Gut Microbiota and Fecal Metabolites

In today's world, unhealthy living habits have contributed to the rise in metabolic disorders like hyperlipidemia. Recognized as a popular edible and medicinal mushroom in China and various eastern nations, <i>Ganoderma lucidum</i> is a promising high-value functional and medicinal food with multiple biological activities. Our earlier research has demonstrated that <i>G. lucidum</i> polysaccharides (GLP) showed distinct lipid-lowering abilities by enhancing the response to oxidative stress and inflammation, adjusting bile acid production and lipid regulation factors, and facilitating reverse cholesterol transport through Nrf2-Keap1, NF-κB, LXRα-ABCA1/ABCG1, CYP7A1-CYP27A1, and FXR-FGF15 pathways, hence we delved deeper into the effects of GLP on hyperlipidemia, focusing on its structural characterization, gut microbiota, and fecal metabolites. Our findings showed that GLP changed the composition and structure of gut microbiota, and 10 key biomarker strains screened by LEfSe analysis markedly increased the abundance of energy metabolism, and cell growth and death pathways which were found by PICRUSt2. In addition, GLP intervention significantly altered the fecal metabolites, which enriched in amino acid metabolism and lipid metabolism pathways. The results of structural characterization showed that GLP, with the molecular weight of 12.53 kDa, consisted of pyranose rings and was linked by α-type and β-type glycosidic bonds, and its overall morphology appeared as an irregular flaky structure with some flecks and holes in the surface. Collectively, our study highlighted that the protective effects of GLP were closely associated with the modification of gut microbiota and the regulation of metabolites profiles, thus ameliorating dyslipidemia.