Hypolipidemic effects of Porphyra haitanensis polysaccharide through the gut-liver axis in high-fat diet fed Mesocricetus auratus

In recent years, hyperlipidemia has become a global public health problem that has severely affected people's physical and mental health, and quality of life. Diet-induced hyperlipidemia interventions using food nutritional components have become a new research focus. Here, Porphyra haitanensis polysaccharide (PHP) was fermented by the gut microbiota, thereby producing short-chain fatty acids that exert hyperlipidemic effects through the gut-liver axis. The present study was aimed at revealing mechanism of PHP in decreasing blood lipids by acting through the gut-liver axis in Mesocricetus auratus hamsters fed a high-fat diet. PHP significantly prevented increases in serum total cholesterol, triglycerides and low-density lipoprotein cholesterol, and alleviated damage to liver cells induced by a high-fat diet, in a dose-dependent manner. PHP promoted the proliferation of Muribaculaceae and Faecalibaculum, thereby enhancing the production of butyric acid, particularly high dose PHP. Low dose PHP promoted the expression of phosphatidylcholine metabolites and fatty acid transport genes, and inhibited the expression of genes involved in fat degradation (Abhd5), adipogenesis (Me1) fatty acid synthesis (Fasn and Pnpla3) and fatty acid chain elongation (Elovl6) in the liver. However, high dose PHP inhibited the expression of triglyceride metabolites and promoted the expression of fatty acid transporter (CD36), fatty acid oxidation (Acacb) and pparg genes in the liver. PHP regulates lipid metabolism through the gut microbiota, and the gut-liver axis plays an important role in its hyperlipidemic effects. Therefore, PHP might be used as an efficacious functional food supplement.