摘要

       铁 (Fe) 已广泛应用于处理砷 (As) 污染的水，Fe 会影响 As 的生物利用度和毒性。然而，人们对 As 和/或 Fe 对肠道微生物群的影响知之甚少，肠道微生物群在宿主健康中起着重要作用。在本研究中，应用高通量测序和定量实时 PCR 来分析 As 和 Fe 对小鼠肠道微生物群的影响。 As和Fe的共同暴露在一定程度上减轻了对微生物群落的影响。相关性分析表明，As 和/或 Fe 暴露引起的肠道微生物群的变化可能是小鼠代谢谱变化的重要原因。对于抗生素抗性基因 (ARG)，As 和 Fe 的共同暴露增加了 ARG 的类型和丰度。但是对于高丰度的 ARG，例如 tetQ、tetO 和 tetM，与单独接触 As 和 Fe 相比，同时接触 As 和 Fe 减轻了对其丰度的影响。未发现 ARG 与可移动遗传元件之间存在明显关系。金属暴露引起的 ARG 变化可能是由于肠道微生物多样性的改变。我们的研究结果表明，As 和/或 Fe 引起的肠道微生物群落变化会影响宿主代谢和肠道中 ARGs 的丰度，表明在评估 As 和/或 Fe 的风险时应考虑肠道微生物群的变化。

       Iron (Fe) has been widely applied to treat arsenic (As)-contaminated water, and Fe could influence bioavailability and toxicity of As. However, little is known about the impact of As and/or Fe on gut microbiota, which plays important roles in host health. In this study, high-throughput sequencing and quantitative real time PCR were applied to analyze the impact of As and Fe on mouse gut microbiota. Co-exposure of As and Fe mitigated effects on microbial community to a certain extent. Correlation analysis showed the shifts in gut microbiota caused by As and/or Fe exposure might be important reason of changes in metabolic profiles of mouse. For antibiotic resistance genes (ARGs), co-exposure of As and Fe increased types and abundance of ARGs. But for high abundance ARGs, such as tetQ, tetO and tetM, co-exposure of As and Fe mitigated effects on their abundances compared to exposure to As and Fe alone. No obvious relationship between ARGs and mobile genetic elements were found. The changes in ARGs caused by metal exposure might be due to the alteration of gut microbial diversity. Our results show that changes of gut microbial community caused by As and/or Fe can influence host metabolisms and abundances of ARGs in gut, indicating that changes of gut microbiota should be considered during the risk assessment of As and/or Fe.

https://www.sciencedirect.com/science/article/abs/pii/S0045653514004172