College of Resources and Environment , University of Chinese Academy of Sciences Beijing 101408 , People's Republic of China.
Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , People's Republic of China.
J Agric Food Chem. 2019 May 1;67(17):4987-4994. doi: 10.1021/acs.jafc.9b02008. Epub 2019 Apr 22.
Despite rice consumption, rice bran as a byproduct of rice milling contains higher arsenic (As). The present study evaluated the metabolic potency of in vitro cultured human colon microbiota toward As from five rice bran products with 0.471-1.491 mg of As/kg. Arsenic bioaccessibility ranged from 52.8 to 78.8% in the gastric phase, and a 1.2-fold increase (66.0-95.8%) was observed upon the small intestinal phase. Subsequently, a significant decline of As bioaccessibility (11.3-63.6%) and a high methylation percentage of 18.5-79.8% were found in the colon phase. The predominant As species in the solid phase was always As(V) (49.6-63.4%), and As-thiolate complexes increased by 10% at the end of colon incubation. Human gut microbiota could induce As bioaccessibility lowering and As transformation in rice bran, which illustrated the importance of food-bound As metabolism in the human body. This will result in a better understanding of health implications associated with As exposures.
尽管食用大米，但大米加工的副产品米糠中含有较高的砷（As）。本研究评估了体外培养的人类结肠微生物群对五种米糠产品中砷的代谢能力，这些产品的砷含量为 0.471-1.491 毫克/千克。在胃阶段，砷的生物可利用性范围为 52.8-78.8%，在小肠阶段观察到 1.2 倍的增加（66.0-95.8%）。随后，在结肠阶段，砷的生物可利用性显著下降（11.3-63.6%），甲基化百分比很高，为 18.5-79.8%。固相中的主要砷形态始终为砷（V）（49.6-63.4%），并且在结肠孵育结束时，砷-硫醇络合物增加了 10%。人类肠道微生物群可以诱导米糠中砷的生物可利用性降低和砷的转化，这说明了食物结合砷代谢在人体中的重要性。这将有助于更好地理解与砷暴露相关的健康影响。
