Natto alleviates hyperlipidemia in high-fat diet-fed mice by modulating the composition and metabolic function of gut microbiota

Background: Hyperlipidemia is a metabolic disease that causes serious health problems for people all around the world. Natto has long been considered as a medical-food dual-use product with anti-fat effect, according to reports. However, the mechanisms of natto in lowering blood lipids remain unknown. The aim of the research is to investigate the potential mechanism of natto for preventing hyperlipidemia. Methods: In the study, three groups of Kunming (KM) mice were fed either normal diets or high-fat diets (HFD), with one of the HFD groups additionally receiving daily natto treatments. After 8 weeks, the mice's blood, liver, cecal contents, and feces were collected. The H&E staining method was used to evaluate the effect of natto on HFD-induced liver damage. The effect of natto on gut microbiota and its metabolites were further investigated through 16S rRNA amplicon sequencing and ultra-high-performance liquid chromatography tandem Q-Exactive Orbitrap mass spectrometry (UPLC-Q-Exactive Orbitrap/MS).