膳食成分对南方稻米中镉生物有效性的调控及其机理研究

我国南方严重的农田污染导致本地稻米中镉含量普遍偏高，民众因而面临较大的镉危害风险。人体实际吸收稻米中镉的水平受诸多因素影响，其中同步进入人体胃肠的其它膳食成分起直接作用。本项目拟采用体外模拟胃肠消化方法、细胞模型和活体动物试验，依据本地民众饮食结构特征选取膳食成分，研究不同膳食成分对大米中镉的生物可给性、生物有效性的影响，分析不同膳食成分对镉在小鼠体内（肾、肝和大腿骨）的累积、肾肝损伤的影响和调控，探明金属硫蛋白在膳食成分共同作用下对镉生物有效性的调控机理，确定南方地区可显著降低镉生物吸收利用水平的膳食成分，制定有益于降低污染区人群健康风险的饮食方案。本项目取得的研究成果，将为应对我国南方大面积农田重金属污染造成的食品安全问题提供新的理论依据和技术对策。

Serious farmland pollution with heavy metals in Southern China has resulted in high cadmium (Cd) level in rice, and people are facing great potential health risks. The accumulation of Cd in human body depended on many factors, and the most important of these is other dietary components which enter into the human gastrointestinal tract with rice. This protocol intends to investigate the effects of different dietary components on the bioaccessibility and bioavailability of Cd in Rice based on in vitro digestion tests, cell model and in vivo bioassay. The effects of different dietary components on the accumulation of Cd in mouse kidney, liver and femur and kidney and liver injury will be analyzed. We intend to explore the regulatory mechanism of metallothionein (Cd-MT) on the bioavailability of Cd resulting from the dietary components that can significantly reduce the Cd bioabsorption in mouse body. Finally, we intend to distinguish some efficient dietary components and formulate a dietary program beneficial to reducing the health risk of inhabitants in contaminated areas in Southern China. Based on the aforementioned results, a new theoretical basis and specific countermeasures will be proposed for food safety problems caused by large-scale farmland pollution in Southern China.