Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
Environ Pollut. 2022 Sep 15;309:119753. doi: 10.1016/j.envpol.2022.119753. Epub 2022 Jul 11.
Arsenic exposure has been reported to alter the gut microbiome in mice. Activity of the gut microbiome derived from fecal microbiota has been found to affect arsenic bioaccessibility in an in vitro gastrointestinal (GI) model. Only a few studies have explored the relation between arsenic exposure and changes in the composition of the gut microbiome and in arsenic bioaccessibility. Here, we used simulated GI model system (GIMS) containing a stomach, small intestine, colon phases and microorganisms obtained from mouse feces (GIMS-F) and cecal contents (GIMS-C) to assess whether exposure to arsenic-contaminated soils affect the gut microbiome and whether composition of the gut microbiome affects arsenic bioaccessibility. Soils contaminated with arsenic did not alter gut microbiome composition in GIMS-F colon phase. In contrast, arsenic exposure resulted in the decline of bacteria in GIMS-C, including members of Clostridiaceae, Rikenellaceae, and Parabacteroides due to greater diversity and variability in microbial sensitivity to arsenic exposure. Arsenic bioaccessibility was greatest in the acidic stomach phase of GIMS (pH 1.5-1.7); except for GIMS-C colon phase exposed to mining-impacted soil in which greater levels of arsenic solubilized likely due to microbiome effects. Physicochemical properties of different test soils likely influenced variability in arsenic bioaccessibility (GIMS-F bioaccessibility range: 8-37%, GIMS-C bioaccessibility range: 2-18%) observed in this study.
砷暴露已被报道会改变小鼠的肠道微生物组。从粪便微生物群衍生的肠道微生物组的活性已被发现会影响体外胃肠道 (GI) 模型中的砷生物可利用性。只有少数研究探讨了砷暴露与肠道微生物组组成和砷生物可利用性变化之间的关系。在这里，我们使用含有胃、小肠、结肠相和从小鼠粪便中获得的微生物的模拟胃肠道 (GIMS)（GIMS-F）和盲肠内容物（GIMS-C）来评估暴露于受砷污染的土壤是否会影响肠道微生物组，以及肠道微生物组的组成是否会影响砷的生物可利用性。砷污染的土壤不会改变 GIMS-F 结肠相中肠道微生物组的组成。相比之下，砷暴露导致 GIMS-C 中的细菌减少，包括梭菌科、真杆菌科和拟杆菌属的成员，这是由于微生物对砷暴露的敏感性存在更大的多样性和可变性。砷的生物可利用性在 GIMS 的酸性胃相中最高（pH 值 1.5-1.7）；除了暴露于受采矿影响的土壤的 GIMS-C 结肠相，由于微生物组的影响，可能会有更多的砷溶解。不同测试土壤的物理化学性质可能会影响砷生物可利用性的可变性（GIMS-F 生物可利用性范围：8-37%，GIMS-C 生物可利用性范围：2-18%）。
