Jiménez-Arroyo C, Tamargo A, Molinero N, Reinosa J J, Alcolea-Rodriguez V, Portela R, Bañares M A, Fernández J F, Moreno-Arribas M V
Institute of Food Science Research, CIAL, CSIC-UAM, C/ Nicolás Cabrera 9, 28049 Madrid, Spain.
Instituto de Cerámica y Vidrio, CSIC, c/ Kelsen, 28049 Madrid, Spain; Encapsulae S.L., c/Lituania 10, 12006 Castellón de la Plana, Spain.
Sci Total Environ. 2023 Dec 1;902:166003. doi: 10.1016/j.scitotenv.2023.166003. Epub 2023 Aug 6.
The accumulation of microplastics (MPs) in the environment as well as their presence in foods and humans highlight the urgent need for studies on the effects of these particles on humans. Polylactic acid (PLA) is the most widely used bioplastic in the food industry and medical field. Despite its biodegradability, biocompatibility, and "Generally Recognized As Safe" (GRAS) status, recent animal model studies have shown that PLA MPs can alter the intestinal microbiota; however, to date, no studies have been reported on the possible gut and health consequences of its intake by humans. This work simulates the ingestion of a realistic daily amount of PLA MPs and their pass through the gastrointestinal tract by combining the INFOGEST method and the gastrointestinal simgi® model to evaluate possible effects on the human colonic microbiota composition (16S rRNA gene sequencing analysis) and metabolic functionality (lactic acid and short-chain fatty acids (SCFA) production). Although PLA MPs did not clearly alter the microbial community homeostasis, increased Bifidobacterium levels tended to increase in presence of millimetric PLA particles. Furthermore, shifts detected at the functional level suggest an alteration of microbial metabolism, and a possible biotransformation of PLA by the human microbial colonic community. Raman spectroscopy and field emission scanning electron microscopy (FESEM) characterization revealed morphological changes on the PLA MPs after the gastric phase of the digestion, and the adhesion of organic matter as well as a microbial biofilm, with surface biodegradation, after the intestinal and colonic phases. With this evidence and the emerging use of bioplastics, understanding their impact on humans and potential biodegradation through gastrointestinal digestion and the human microbiota merits critical investigation.
微塑料（MPs）在环境中的积累及其在食品和人体中的存在凸显了对这些颗粒对人类影响进行研究的迫切需求。聚乳酸（PLA）是食品工业和医疗领域中使用最广泛的生物塑料。尽管它具有生物可降解性、生物相容性以及“一般认为安全”（GRAS）的地位，但最近的动物模型研究表明，聚乳酸微塑料可以改变肠道微生物群；然而，迄今为止，尚未有关于人类摄入聚乳酸微塑料可能对肠道和健康产生的影响的研究报道。这项工作通过结合INFOGEST方法和胃肠道simgi®模型，模拟了人类每日实际摄入的聚乳酸微塑料及其在胃肠道中的通过过程，以评估其对人类结肠微生物群组成（16S rRNA基因测序分析）和代谢功能（乳酸和短链脂肪酸（SCFA）产生）的可能影响。尽管聚乳酸微塑料没有明显改变微生物群落的稳态，但在存在毫米级聚乳酸颗粒的情况下，双歧杆菌水平有增加的趋势。此外，在功能水平上检测到的变化表明微生物代谢发生了改变，并且人类结肠微生物群落可能对聚乳酸进行了生物转化。拉曼光谱和场发射扫描电子显微镜（FESEM）表征显示，在消化的胃阶段后，聚乳酸微塑料的形态发生了变化，在肠道和结肠阶段后，有有机物以及微生物生物膜的附着，并伴有表面生物降解。有了这些证据以及生物塑料的新兴应用，了解它们对人类的影响以及通过胃肠道消化和人类微生物群进行潜在生物降解的情况值得进行关键研究。
