College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China.
College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China.
Sci Total Environ. 2018 Aug 1;631-632:449-458. doi: 10.1016/j.scitotenv.2018.03.051. Epub 2018 Mar 16.
Microplastic (MP) has become a concerning global environmental problem. It is toxic to aquatic organisms and can spread through the food chain to ultimately pose a threat to humans. In the environment, MP can interact with microbes and act as a microbial habitat. However, effects of polystyrene MP on the gut microbiota in mammals remain unclear. Here, male mice were exposed to two different sizes of polystyrene MP for 5 weeks to explore its effect. We observed that oral exposure to 1000 μg/L of 0.5 and 50 μm polystyrene MP decreased the body, liver and lipid weights in mice. Mucus secretion in the gut decreased in both sizes of polystyrene MP-treated groups. Regarding the gut microbiota, at the phylum level, polystyrene MP exposure decreased the relative abundances of Firmicutes and α-Proteobacteria in the feces. Furthermore, high throughput sequencing of the V3-V4 region of the 16S rRNA gene revealed significant changes in the richness and diversity of the gut microbiota in the cecums of polystyrene MP-treated mice. At the genus level, a total of 6 and 8 types of bacteria changed in the 0.5 and 50 μm polystyrene MP-treated groups, respectively. Furthermore, an operational taxonomic unit (OTU) analysis identified that 310 and 160 gut microbes were changed in the 0.5 and 50 μm polystyrene MP-treated groups, respectively. In addition, the hepatic triglyceride (TG) and total cholesterol (TCH) levels decreased in both 1000 μg/L 0.5 and 50 μm polystyrene MP-treated groups. Correspondingly, the relative mRNA levels of some key genes related to lipogenesis and TG synthesis decreased in the liver and epididymal fat. These results indicated that polystyrene MP could modify the gut microbiota composition and induce hepatic lipid disorder in mice; while the mouse is a common mammal model, consequently, the health risks of MP to animals should not be ignored.
微塑料（MP）已成为全球关注的环境问题。它对水生生物有毒，可通过食物链传播，最终对人类构成威胁。在环境中，MP 可以与微生物相互作用并充当微生物栖息地。然而，聚苯乙烯 MP 对哺乳动物肠道微生物群的影响尚不清楚。在这里，雄性小鼠暴露于两种不同尺寸的聚苯乙烯 MP 中 5 周，以探索其影响。我们观察到，口服 1000μg/L 的 0.5 和 50μm 聚苯乙烯 MP 会降低小鼠的体重、肝脏和脂质重量。两种尺寸的聚苯乙烯 MP 处理组的肠道粘液分泌减少。关于肠道微生物群，在门水平上，暴露于聚苯乙烯 MP 会降低粪便中厚壁菌门和α变形菌门的相对丰度。此外，16S rRNA 基因 V3-V4 区的高通量测序显示，聚苯乙烯 MP 处理组小鼠盲肠肠道微生物群的丰富度和多样性发生了显著变化。在属水平上，0.5 和 50μm 聚苯乙烯 MP 处理组分别有 6 种和 8 种细菌发生变化。此外，操作分类单元（OTU）分析鉴定出 0.5 和 50μm 聚苯乙烯 MP 处理组分别有 310 种和 160 种肠道微生物发生变化。此外，1000μg/L 的 0.5 和 50μm 聚苯乙烯 MP 处理组的肝甘油三酯（TG）和总胆固醇（TCH）水平均降低。相应地，肝脏和附睾脂肪中与脂肪生成和 TG 合成相关的一些关键基因的相对 mRNA 水平降低。这些结果表明，聚苯乙烯 MP 可以改变肠道微生物群组成，并在小鼠中诱导肝脂质紊乱；而小鼠是常见的哺乳动物模型，因此，不应忽视 MP 对动物的健康风险。
