Enzyme-hydrolyzed polysaccharides from Morchella importuna: preparation, structural characterization, and multi-omics...

Metabolic disorders induced by a high-fat diet (HFD) represent a major global health burden. Natural polysaccharides possess lipid-lowering activity, but their high molecular weight often limits bioavailability. In this study, a low-molecular-weight polysaccharide, EMIP, was prepared through the enzymatic degradation of Morchella importuna polysaccharide (MIP). EMIP exhibited significantly enhanced antioxidant and pancreatic lipase inhibitory activities in vitro. In HFD-fed mice, EMIP more effectively reduced serum and hepatic lipid levels, improved liver function, and alleviated oxidative stress and inflammatory responses. Multi-omics analysis further revealed that EMIP modulated the gut microbiota (e.g., enriching Lactobacillus and reducing Dubosiella) and regulated key liver metabolites such as lyso-phosphatidylglycerol, lyso-phosphatidylcholine, and 8-aminooctanoic acid-a novel potential biomarker for lipid metabolism disorders. KEGG pathway analysis indicated that EMIP regulated lipid metabolism via pathways related to amino acids and hormones, providing new insights into the intervention of metabolic syndrome with functional polysaccharides.