植物油是我国居民膳食摄入植物甾醇的主要来源。由于植物甾醇的生物利用度低下，导致其真实摄入水平远低于营养学的推荐值。不同植物油中甘油酯组成及植物甾醇结构的差异可能是影响植物甾醇生物利用度的关键因素。本项目拟整合油脂化学、脂质组学、分子生物学和代谢组学的科学思路，首先利用人工胶粒模型结合核磁共振成像技术，表征植物甾醇在膳食混合胶粒中溶解的热力学规律；其次利用体外模拟消化手段，描述植物甾醇在膳食混合胶粒复杂体系中缔合的动力学过程；再次利用Caco-2细胞模型分析植物甾醇在小肠上皮细胞中的代谢规律，揭示胞内胆固醇酰基转移酶和相关转运蛋白的作用机理。最终在胶粒溶解度、细胞吸收率和生物转化率三个层面，阐明植物油中甘油酯及植物甾醇的组成影响植物甾醇生物利用度的分子机制。通过本项目的实施，可以在不改变我国居民膳食结构和习惯的条件下，为提高居民膳食来源植物甾醇的生物利用度提供理论依据，具有重要的现实意义。

In China, vegetable oil is the main source of dietary phytosterol. However, the low bioavailability of phytosterols resulted in a poor intake of phytosterols, which is far below the value of nutritional recommendation. The differences in triacylglycerol of vegetable oils and structure of phytosterols may play a critical role in the bioavailability of phytosterols. By integrating the strategies of lipid chemistry, lipidomics, molecular biology, and metabolomics, the current project aims to elucidate the mechanism that how the phytosterols bioavailability was affected by triacylglycerol compositions and phytosterols structure from the aspect of micelles solubility, absorption and biotransformation. Firstly, the thermodynamics behavior of phytosterols in dietary mixed micelles will be characterized by using the artificial mixed micelles model combined with Magnetic Resonance Imaging technology. Secondly, the in-vitro simulated digestion model will be further performed to evaluate the hydrophobic association kinetics of phytosterols in the complex mixed micelles system. Finally, the Caco-2 cell will be utilized to simulate the uptake of phytosterols in intestinal epithelial cells, trying to reveal the absorption mechanism related to intracellular cholesterol acyltransferase and other transport proteins. Through the implementation of this project, it will be feasible to improve the bioavailability of dietary phytosterols without changing the habits, which is of great practical significance for safeguarding the national nutrition and health.