非酒精性脂肪肝病（NAFLD）严重威害人类健康，目前尚无特效治疗药。最新研究显示肝脏-胆汁酸-肠道菌群代谢轴（LBGMA）在NAFLD发生发展中起重要作用，为其防治提供了新思路。已有研究表明植物化学物大豆皂甙（SS）具有肝保护、抗炎等多种可减轻或消除NAFLD危险因素的生物活性，我们前期在高脂诱导的肥胖小鼠模型中发现SS可减轻肝脏脂肪变性和炎症，提示其可能具有防治NAFLD的效果，且我们和他人的研究均表明SS在肠道内会被菌群代谢并与胆汁酸发生互作，但目前未见有关SS预防NAFLD及其机理的报道。本课题拟运用蛋氨酸-胆碱缺乏饲料诱导小鼠建立NAFLD模型，用三种不同化学结构SS进行预防性干预，进一步研究它们对LBGMA的调控作用，旨在证实SS预防NAFLD的活性，揭示其构效关系，并阐明其作用机理，为从营养学上合理运用SS类植物化学物预防NAFLD提供理论依据，也为药学上开发治疗药物提供线索。

Nonalcoholic fatty liver disease (NAFLD) seriously threats human health. No specific medicine is currently available. Latest studies suggest that the Liver-Bile acid-Gut Microbiota Metabolic Axis (LBGMA) plays vital roles in the occurrence and development of NAFLD, which provides new clues for NAFLD's prevention and therapy. Existing evidences show that phytochemical soyasaponin (SS) have many biological activities (eg. hepatoprotection, anti-inflammation, etc.) which can help to reduce or clear the risk factors of NAFLD. We previously found that SS reduced hepatic steatosis and inflammation in high fat diet-induced obese mice. This suggests that SS may have the potential abilities to prevent and treat NAFLD. Moreover, we and others have shown that SS can be metabolized by gut microbiota and interacted with bile acids in the intestine. However, no report is available regarding SS's preventive abilities against NAFLD and its mechanism. In this study, we are going to firstly establish the methionine and choline deficiency (MCD) feed-induced NAFLD mice model and then investigate the effects of SS with three different chemical structures on the occurrence and development of NAFLD and further study their regulation on LBGMA. The purpose of the study is to confirm the preventive bioactivities of SS against NAFLD, uncover their chemical structure-bioactivity relationships and clarify the underlying mechanism. Accomplishment of this program will provide theoretical basis for using phytochemical soyasaponins to prevent NAFLD in nutrition and potential clues for developing therapeutic medicine in pharmacy.