Porphyra haitanensis Polysaccharides Attenuates Blood Lipid via Gut‐Liver Axis in Diet‐Induced High‐Fat Mesocricetus auratus through Multiple Integrated Omics

Scope Hyperlipidemia is currently a global public health problem severely affecting people's physical and mental health, as well as their quality of life. Methods and results The present study is aimed at revealing the mechanism of Porphyra haitanensis polysaccharide (PHP) in decreasing blood lipids by acting through gut‐liver axis in Mesocricetus auratus 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 M. auratus , in a dose‐dependent manner. PHP promotes proliferation of Muribaculaceae and Faecalibaculum, thereby enhancing the production of butyric acid both in the colon and liver, particularly high‐dose PHP (HPHP). Low‐dose PHP (LPHP) promotes the expression of phosphatidylcholine metabolites and fatty acid transport genes, and inhibits 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, HPHP inhibits the expression of triglyceride metabolites and promotes the expression of fatty acid transporter (CD36), fatty acid oxidation (Acacb), and peroxisome proliferator‐activated receptor gamma (PPARg) genes in the liver. Conclusion PHP regulates lipid metabolism through the gut microbiota, and the gut‐liver axis plays an important role in its hypolipidemic effects.