肠道微生物对蔬菜中铬生物可给性的影响及人体健康风险评价

Effect of gut microbiota on bioaccessibility of chromium in vegetables and human health risk assessment

为更加全面、准确评估蔬菜中重金属铬(Cr)生物可给性及对人体健康风险的影响,本文利用生物原理提取法(physiologically based extraction test,PBET)联合微生物生态系统(simulator of human intestinal microbial ecosystem,SHIME)模拟实验,系统分析了贵州某铅锌矿区4种常见蔬菜(辣椒、芥菜、小白菜和甘蓝)在不同食用条件(生和熟)下Cr的含量变化,探究在肠道微生物影响下蔬菜Cr在不同消化吸收阶段(胃、小肠和结肠)中生物可给性差异,并对比了各消化阶段的膳食暴露风险.结果表明,4种蔬菜样品中Cr的含量(干重)表现为小白菜(13.86±7.33)mg·kg^(−1)>芥菜(9.84±1.79)mg·kg^(−1)>甘蓝(9.53±1.60)mg·kg^(−1)>辣椒(5.28±2.48)mg·kg^(−1);虽煮熟处理可显著降低4种蔬菜样品中的Cr含量(降低范围54.98%—63.44%,P<0.05),但生熟蔬菜样品中Cr含量仍超过国家食品卫生标准中的标准限值(GB 2762—2017:0.5 mg∙kg^(−1)).此外,研究发现结肠阶段中Cr的生物可给性最高,分别为成人:(22.56%±9.23%)—(36.04%±11.45%);儿童:(19.74%±8.26%)—(34.53%±10.82%),分别是小肠阶段的1.10—6.00倍和1.05—5.77倍,且蔬菜高温处理后增加了结肠阶段Cr的生物可给性(6.11%—21.51%).对比各消化阶段的危害商指数(HQ)发现,基于结肠阶段生物可给性计算的HQ累计概率较高,相比小肠阶段提高了约6.17%—62.12%,表明结肠阶段中肠道微生物作用下可增加蔬菜中Cr的生物可给性和提高人体健康风险.因此,在未来开展人体健康风险评估时,需综合评估不同食用条件下食物中重金属在结肠阶段中生物可给性的健康风险,以期为我国膳食重金属暴露的人体健康风险评估提供更多科学参考.

To more comprehensively and accurately assess the bioaccessibility of Chromium(Cr)in vegetables and its human health risk,the PBET method combined with SHIME model was used to determine the vegetable concentration of Cr in different treatments(raw and cooked)and the effects of gut microbiota on Cr bioaccessibility.Four common vegetables(pepper,mustard,pakchoi and cabbage)were collected from Lead-Zinc mining region in Guizhou Province.The results showed that the contents(dry weight)of Cr in the four varieties of vegetables were pakchoi(13.86±7.33)mg·kg^(−1)>mustard(9.84±1.79)mg·kg^(−1)>cabbage(9.53±1.60)mg·kg^(−1)>pepper(5.28±2.48)mg·kg^(−1).Although the cooking process could significantly reduce the contents of Cr in vegetables(range of 54.98%—63.44%,P<0.05),the contents of Cr both in raw and cooked vegetable samples were still exceeds limit standard of Cr stipulated in the National Food Hygiene Standard(GB 2762—2017:0.5 mg·kg^(−1)).In addition,the study found that the highest bioaccessibility of Cr in the colon phase,adult:(22.56%±9.23%)—(36.04%±11.45%);child:(19.74%±8.26%)—(34.53%±10.82%),which was 1.10—6.00 times and 1.05—5.77 times higher than those in the small intestine phase,respectively.And the cooking process significantly increased the bioaccessibility of Cr in the colon phase(6.11%—21.51%).Compared with the hazard quotient(HQ)in different digestion phases,the cumulative probability of HQ calculated based on the bioaccessibility of Cr in the colon phase showed higher health risk,which was about 6.17%—62.12%higher than in the small intestinal phase.The result indicated that the gut microbiota in the colon phase could increase the bioaccessibility of Cr in vegetables and improve human health risk.Therefore,it was necessary to comprehensively evaluate the bioaccessibility of heavy metals in foods in the colon phase under different edible conditions in future research,to provide more scientific reference for human health risk assessment of dietary heavy metal exposure.