School of Public Health, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang, 550025, China.
Hubei Key Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China.
Bull Environ Contam Toxicol. 2022 Sep;109(3):534-541. doi: 10.1007/s00128-022-03569-5. Epub 2022 Jul 25.
This study aims to investigate methylmercury (MeHg) demethylation processes in human gut. Here, we determined the compositions and MeHg demethylation rates of gut microbiota in residents from different Hg exposure levels (Wanshan (WS) town and Yangtou (YT) town) and different Hg exposure sources (Zhuchang (ZC) town and YT town) regions. MeHg and inorganic Hg exposure levels in residents of WS town were significantly higher than those of YT and ZC town. Desulfovibrio and Methanogens, which related to Hg methylation/demethylation, showed significantly higher abundance in WS and ZC, comparing with YT. In vitro experiments demonstrated that human intestinal microbiota could degrade MeHg directly. Besides, gut microbiota in WS and ZC exhibited significantly higher demethylation rates than YT, suggesting Desulfovibrio and Methanogens may play important roles in intestinal MeHg demethylation. This study highlights Hg exposure levels and sources may affect demethylation efficiency of gut microbiota, which provides new insights for MeHg demethylation processes in human body.
本研究旨在探究人体肠道中甲基汞（MeHg）的脱甲基过程。在此，我们测定了来自不同汞暴露水平（万山（WS）镇和杨头（YT）镇）和不同汞暴露源（竹厂（ZC）镇和 YT 镇）地区居民肠道微生物群的组成和 MeHg 脱甲基率。WS 镇居民的 MeHg 和无机汞暴露水平明显高于 YT 和 ZC 镇。与汞甲基化/脱甲基相关的脱硫弧菌属和产甲烷菌属在 WS 和 ZC 中的丰度明显高于 YT。体外实验表明，人肠道微生物群可以直接降解 MeHg。此外，WS 和 ZC 的肠道微生物群表现出比 YT 更高的脱甲基率，这表明脱硫弧菌属和产甲烷菌属可能在肠道 MeHg 脱甲基中发挥重要作用。本研究强调了汞暴露水平和来源可能会影响肠道微生物群的脱甲基效率，为人体中 MeHg 的脱甲基过程提供了新的见解。
