Microplastics in the human digestive environment: A focus on the potential and challenges facing in vitro gut model development

Plastic pollution is a major issue worldwide, generating massive amounts of smaller plastic particles, including microplastics (MPs). Their ubiquitous nature in the environment but also in foodstuff and consumer packaged goods has revealed potential threats to humans who can be contaminated mainly through air, food and water consumption. In this review, the current literature on human exposure to MPs is summarized with a focus on the gastrointestinal tract as portal of entry. Then, we discuss the vector effect of MPs, in their pristine versus weathered forms, with well-known contaminants as heavy metals and chemicals, or more emerging ones as antibiotics or microbial pathogens, like Pseudomonas spp., Vibrio spp., Campylobacter spp. and Escherichia coli. Comprehensive knowledge on MP fate in the gastrointestinal tract and their potential impact on gut homeostasis disruption, including gut microbiota, mucus and epithelial barrier, is reported in vitro and in vivo in mammals. Special emphasis is given on the crucial need of developing robust in vitro gut models to adequately simulate human digestive physiology and absorption processes. Finally, this review points out future research directions on MPs in human intestinal health.

Automated summary

Plastic pollution, especially microplastics, poses potential threats to human health as they can contaminate humans mainly through air, food, and water consumption. Microplastics can interact with well-known contaminants such as heavy metals and chemicals, as well as emerging ones like antibiotics or microbial pathogens in the environment. Understanding the fate of microplastics in the gastrointestinal tract and their impact on gut homeostasis disruption, as well as the development of robust in vitro gut models to simulate human digestive physiology, are crucial for future research on human intestinal health.