Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
Food Chem Toxicol. 2024 Mar;185:114474. doi: 10.1016/j.fct.2024.114474. Epub 2024 Feb 1.
Biodegradable plastics, were considered environmentally friendly, may produce more microplastic particles (MPs) within the same period and exert more pronounced adverse effects on human health than traditional non-biodegradable plastics. Thus, this study investigated the changes of two kinds of biodegradable MPs from different sources in the digestive tract by using simulated digestion and fermentation models in vitro, with particle size, scanning electron microscopy (SEM) and gel permeation chromatography (GPC) analysis, and their implications on the gut microbiota were detected by full-length bacterial 16S rRNA gene amplicon sequencing. Poly(ε-caprolactone) (PCL) MPs exhibited stability in the upper gastrointestinal tract, while poly(lactic acid) (PLA) MPs were degraded beginning in the small intestine digestion phase. Both PCL and PLA MPs were degraded and oligomerized during colonic fermentation. Furthermore, this study highlighted the disturbance of the gut microbiota induced by MPs and their oligomers. PCL and PLA MPs significantly changed the composition and reduced the α-diversity of the gut microbiota. PCL and PLA MPs exhibited the same inhibitory effects on key probiotics such as Bifidobacterium, Lactobacillus, Faecalibacterium, Limosilactobacillus, Blautia, Romboutsia, and Ruminococcus, which highlighted the potential hazards of these materials for human health. In conclusion, this study illuminated the potential biodegradation of MPs through gastrointestinal digestion and the complex interplay between MPs and the gut microbiota. The degradable characteristic of biodegradable plastics may cause more MPs and greater harm to human health.
可生物降解塑料被认为是环保的，但在相同的时间内，它们可能会产生更多的微塑料颗粒（MPs），并对人类健康产生更明显的不利影响，比传统的不可生物降解塑料更甚。因此，本研究通过体外模拟消化和发酵模型，研究了两种不同来源的可生物降解 MPs 在消化道中的变化，采用粒径、扫描电子显微镜（SEM）和凝胶渗透色谱（GPC）分析，并通过全长细菌 16S rRNA 基因扩增子测序检测其对肠道微生物群的影响。聚己内酯（PCL） MPs 在胃肠道上部表现出稳定性，而聚乳酸（PLA） MPs 则在小肠消化阶段开始降解。PCL 和 PLA MPs 均在结肠发酵过程中降解和低聚化。此外，本研究强调了 MPs 和它们的低聚物对肠道微生物群的干扰。PCL 和 PLA MPs 显著改变了肠道微生物群的组成，并降低了其 α-多样性。PCL 和 PLA MPs 对双歧杆菌、乳杆菌、粪杆菌、嗜淀粉瘤胃球菌、罗氏菌和瘤胃球菌等关键益生菌表现出相同的抑制作用，这突出了这些材料对人类健康的潜在危害。总之，本研究阐明了 MPs 通过胃肠道消化的潜在生物降解性，以及 MPs 和肠道微生物群之间的复杂相互作用。可生物降解塑料的可降解特性可能会导致更多的 MPs 并对人类健康造成更大的危害。
