Potential effects of MPs and their co-pollutants on human intestinal tract

Microplastics (MPs), which are tiny plastic particles measuring less than 5 mm, have sparked public concern in recent years. When exposed to the environment, MPs absorb a variety of pollutants, leading to joint damage to human digestive system and other tissues. Human exposure to MPs mainly through food intake, resulting in potential risk of intestinal tract. Research have demonstrated that MPs compromise intestinal integrity and disrupt microbiota, as well as traverse into systemic circulation, posing threat to other tissues in our body. Morever, the MPs also serve as the "carrier" of the pollutants in the environment, such as organic compound, heavy metal and marine pollutant. The interaction between co-pollutants and MPs will influence their physical and chemical properties, producing dual toxic effects on intestinal system. However, the uptake and digestion process of MPs and their co-pollutants in the human body, the extent and mechanism of intestinal damage remain obscure. This review synthesizes current knowledge on MPs' uptake and digestion process in the gut, elucidating the pathogenesis of MPs and their co-pollutant induced damage on intestinal physical, microbiota and immune barrier.