Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China.
Jinan Eco-environmental Monitoring Center, Jinan, 250010, China.
Chemosphere. 2020 Aug;252:126522. doi: 10.1016/j.chemosphere.2020.126522. Epub 2020 Mar 30.
There is limited research on the effects of gut microbiota on bioaccessibility of heavy metals in wheat grains. In this study, bioaccessibility of heavy metals (Cu, Cd, Pb, and Zn) in wheat was determined to elucidate transfer characteristics in the soil-grain-human systems near two large-scale mining areas in Shandong Province, North China using the physiologically-based extraction test (PBET) in combination with a simulator of human intestinal microbial ecosystems (SHIME). The results showed the bioconcentration factors (BCFs) of Cu, Cd, Pb, and Zn were 0.123-0.327, 0.188-0.478, 0.019-0.099, and 0.262-0.825, respectively. Significant and positive correlations were observed between heavy metals in soils and wheat grains. In the simulated colon phase, bioaccessibility of Cd and Zn significantly decreased to 7.81% and 8.81%, respectively, being 53% and 64% of that in the simulated small intestinal phase. However, bioaccessibility of Pb showed an obvious escalating trend, being 2.4 times higher than that of intestinal incubation. Based on the estimated daily intakes and contribution, the relative high contribution of Cu to the benchmark dose in both phases, Cu metabolism by human gut microbiota should be considered in human health risk assessment regarding wheat consumption.
关于肠道微生物群对小麦中重金属生物可给性的影响的研究有限。本研究采用基于生理学的提取试验（PBET）结合人体肠道微生物生态系统模拟器（SHIME），测定了山东省两个大型矿区附近土壤-谷物-人体系统中重金属（Cu、Cd、Pb 和 Zn）的生物可给性，以阐明其转移特征。结果表明，Cu、Cd、Pb 和 Zn 的生物浓缩系数（BCF）分别为 0.123-0.327、0.188-0.478、0.019-0.099 和 0.262-0.825。土壤和小麦籽粒中重金属之间存在显著的正相关关系。在模拟结肠阶段，Cd 和 Zn 的生物可给性分别显著降低至 7.81%和 8.81%，分别为模拟小肠阶段的 53%和 64%。然而，Pb 的生物可给性呈明显上升趋势，是肠孵育的 2.4 倍。基于估计的每日摄入量和贡献率，在两个阶段，Cu 对基准剂量的相对高贡献率，应考虑人体肠道微生物群对 Cu 代谢，在涉及小麦消费的人体健康风险评估中。
