Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, China.
Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, China.
Sci Total Environ. 2021 Jul 15;778:146264. doi: 10.1016/j.scitotenv.2021.146264. Epub 2021 Mar 8.
Microplastics (MPs) pollution becomes an emergent threat to the ecosystem, and its joint effect with organic contaminants will cause more severe consequences. Recently, MPs has been observed in human feces, suggesting that we are exposed to an uncertain danger. In this study, the joint effect of polyethylene microplastics particles (PEMPs) and Tetrabromobisphenol A (TBBPA) on human gut was explored through the simulation experiment in vitro with human cell Caco-2 and gut microbiota. The toxicity of TBBPA and PEMPs on Caco-2 human cells was considered by physiological and biochemical indexes such as cell proliferation, cell cycle, reactive oxygen species, lactate dehydrogenase release, and mitochondrial membrane potential. Besides, microbial community diversity, community structure, and function changes of gut microbiota were investigated using Illumina 16S rRNA gene MiSeq sequencing to reveal the influence of TBBPA and PEMPs on human gut microbiota. The results indicated that both PEMPs and TBBPA would deteriorate the status of Caco-2 cells, and TBBPA played a major role in it; meanwhile, PEMPs affected Caco-2 cells at high concentrations. Particularly, TBBPA and PEMPs exhibited a joint effect on Caco-2 cells to a certain degree. TBBPA selectivity inhibited the growth of gram-positive bacteria such as Enterococcus and Lactobacillus, contributing to the thriving of gram-negative bacteria such as Escherichia and Bacteroides. The existence of PEMPs would enhance the proportion of Clostridium, Bacteroides, and Escherichia. Community composition changed dramatically with the interference of PEMPs and TBBPA; this was undesirable to the healthy homeostasis of the human gut. PICRUSt analysis determined both PEMPs and TBBPA interfered with the metabolism pathways of gut microbiota. Hence, the threat of MPs and TBBPA to humans should arouse vigilance.
微塑料（MPs）污染对生态系统构成了新的威胁，其与有机污染物的联合效应将造成更严重的后果。最近，在人类粪便中观察到了 MPs，这表明我们正面临着不确定的危险。本研究通过体外人源 Caco-2 细胞和肠道微生物群落模拟实验，探究了聚乙烯微塑料颗粒（PEMPs）和四溴双酚 A（TBBPA）对人体肠道的联合作用。通过细胞增殖、细胞周期、活性氧、乳酸脱氢酶释放和线粒体膜电位等生理生化指标，考虑了 TBBPA 和 PEMPs 对 Caco-2 人源细胞的毒性。此外，通过 Illumina 16S rRNA 基因 MiSeq 测序研究了肠道微生物群落的多样性、群落结构和功能变化，以揭示 TBBPA 和 PEMPs 对人体肠道微生物群落的影响。结果表明，PEMPs 和 TBBPA 都会使 Caco-2 细胞的状态恶化，且 TBBPA 起主要作用；同时，PEMPs 在高浓度下也会影响 Caco-2 细胞。特别是，TBBPA 和 PEMPs 对 Caco-2 细胞表现出一定程度的联合作用。TBBPA 选择性地抑制了革兰氏阳性菌如肠球菌和乳杆菌的生长，促进了革兰氏阴性菌如大肠杆菌和拟杆菌的生长。PEMPs 的存在会增加梭菌、拟杆菌和大肠杆菌的比例。PEMPs 和 TBBPA 的干扰使群落组成发生了巨大变化，这对人体肠道的健康平衡是不利的。PICRUSt 分析确定 PEMPs 和 TBBPA 均干扰了肠道微生物群落的代谢途径。因此，MPs 和 TBBPA 对人类的威胁应引起警惕。
