Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, PR China.
Hangzhou Hydrology and Water Resources Monitoring Central Station, Hangzhou, 310016, Zhejiang, PR China.
J Hazard Mater. 2018 Aug 5;355:111-118. doi: 10.1016/j.jhazmat.2018.05.011. Epub 2018 May 7.
Oral exposure is a major route of human bisphenol A (BPA) exposure. However, influence of gastrointestinal tract on BPA metabolism is unavailable. In this study, in vitro simulator of the human intestinal microbial ecosystem (SHIME) was applied to investigate the changes in bioaccessibility and metabolism of BPA in different parts of gastrointestinal tract (stomach, small intestine and colon). Then the human hepatoma cell line HepG2 was employed to compare toxic effects of BPA itself and effluents of SHIME system on hepatic gene expression profiles. Results showed that level of bioaccessible BPA decreased with the process of gastrointestinal digestion. But the gastrointestinal digestion could not completely degrade BPA. Then, BPA exposure significantly changed microbial community in colons and increased the percentage of microbes shared in ascending, transverse and descending colons. Abundances of BPA-degradable bacteria, such as Microbacterium and Alcaligenes, were up-regulated. Further, SHIME effluents significantly up-regulated expressions of genes related to estrogenic effect and oxidative stress compared to BPA itself, but reduced or had little change on the risk of cell apoptosis and fatty deposits. This study sheds new lights on influence of gastrointestinal digestion on bioaccessibility and toxic effects of BPA.
经口摄入是人类双酚 A（BPA）暴露的主要途径。然而，胃肠道对 BPA 代谢的影响尚不清楚。在这项研究中，应用了人类肠道微生物生态系统的体外模拟物（SHIME）来研究 BPA 在胃肠道不同部位（胃、小肠和结肠）的生物可及性和代谢变化。然后，用人肝癌细胞系 HepG2 比较 BPA 本身和 SHIME 系统流出物对肝基因表达谱的毒性效应。结果表明，生物可及性 BPA 的水平随着胃肠道消化过程的进行而降低。但是，胃肠道消化并不能完全降解 BPA。然后，BPA 暴露显著改变了结肠中的微生物群落，并增加了升结肠、横结肠和降结肠中共享微生物的比例。可降解 BPA 的细菌，如微杆菌属和产碱杆菌属，丰度增加。此外，与 BPA 本身相比，SHIME 流出物显著上调了与雌激素效应和氧化应激相关的基因表达，但对细胞凋亡和脂肪沉积的风险降低或几乎没有变化。这项研究为胃肠道消化对 BPA 的生物可及性和毒性影响提供了新的见解。
