PET microplastics affect human gut microbiota communities during simulated gastrointestinal digestion, first evidence of plausible polymer biodegradation during human digestion

Microplastics (MPs) are a widely recognized global problem due to their prevalence in natural environments and the food chain. However, the impact of microplastics on human microbiota and their possible biotransformation in the gastrointestinal tract have not been well reported. To evaluate the potential risks of microplastics at the digestive level, completely passing a single dose of polyethylene terephthalate (PET) through the gastrointestinal tract was simulated by combining a harmonized static model and the dynamic gastrointestinal simgi model, which recreates the different regions of the digestive tract in physiological conditions. PET MPs started several biotransformations in the gastrointestinal tract and, at the colon, appeared to be structurally different from the original particles. We report that the feeding with microplastics alters human microbial colonic community composition and hypothesize that some members of the colonic microbiota could adhere to MPs surface promoting the formation of biofilms. The work presented here indicates that microplastics are indeed capable of digestive-level health effects. Considering this evidence and the increasing exposure to microplastics in consumer foods and beverages, the impact of plastics on the functionality of the gut microbiome and their potential biodegradation through digestion and intestinal bacteria merits critical investigation.

Automated summary

Microplastics are a recognized global problem due to their presence in natural environments and the food chain. This study found that microplastics not only have an impact on human microbiota, but also undergo biotransformation in the gastrointestinal tract. The researchers observed that microplastics alter the composition of the human colonic microbial community, and hypothesized that some members of the microbiota adhere to the surface of microplastics, promoting the formation of biofilms. Considering the increasing exposure to microplastics in consumer products, it is important to investigate the effects of plastics on gut microbiome functionality and their potential degradation by intestinal bacteria.