There are increasingly attentions on the pollution from microplastics, especially the impact on human health. This work focuses on one hand the effect of digestion system on the surface microstructures of microplastics from the most popular sources such as polypropylene, polyethylene, polyethylene terephthalate, polystyrene and polyvinyl chloride. On the other hand, how these microplastic affect probiotics in digestion system was also investigated to evaluate their toxicity on health. All the samples were treated by in vitro simulating digestion consisting of three phases: oral, gastric and intestinal. There were no physical differences observed by both Scanning Electronic Microscopy and Atomic Force Microscopy, and no significant chemical changes detected by both Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy after digestion treatment. The effect of these microplastics on tested strains were investigated by in vitro culture method and results showed that polystyrene microplastics could inhibit the growth of the Lactobacillus significantly. The results indicated that the digestion system could not decompose microplastics, even on the surfaces, since plastics are inert due to their low chemical reactivity, but the microplastics might lead to imbalance of intestinal microbiota.

微塑料的污染，尤其是对人体健康的影响越来越受到人们的关注。这项工作一方面侧重于消解系统对聚丙烯、聚乙烯、聚对苯二甲酸乙二醇酯、聚苯乙烯和聚氯乙烯等最流行来源的微塑料表面微结构的影响。另一方面，还研究了这些微塑料如何影响消化系统中的益生菌，以评估它们对健康的毒性。所有样品均通过体外模拟消化处理，包括三个阶段：口服、胃和肠。扫描电子显微镜和原子力显微镜都没有观察到物理差异，消化处理后傅里叶变换红外光谱和X射线光电子能谱均未检测到明显的化学变化。通过体外培养法研究了这些微塑料对受试菌株的影响，结果表明聚苯乙烯微塑料可以显着抑制乳酸杆菌的生长。结果表明，消化系统无法分解微塑料，即使是在表面上，因为塑料由于其低化学反应性而具有惰性，但微塑料可能导致肠道微生物群的不平衡。