Quantitative Lipidomic Analysis of Mouse Digestive System Under Long-Term Microplastic Exposure at Environmentally Relevant Concentrations

Abstract

The effects of long-term exposure to environmentally relevant concentrations of microplastics (MPs) on the mouse digestive system remain limited. In the present study, we investigated the systemic toxicity of digestive system, focusing on stomach, small intestine, and large intestine. Mice were exposed to different sizes (50 nm and 1-4 μm) and types (polystyrene and polyethylene) of MPs at a dose of 167 ng/day over three different periods (1, 3, and 6 months). Lipidomic analysis revealed significant disruptions in lipid metabolism, affecting a total of 10 lipid subclasses. Specifically, we observed significantly changed lipids in glycerolipids, glycerophospholipids, sterol lipids, and fatty acids categories were altered following MP exposure. Those altered lipids results suggested that the effects of MPs may be related to mitochondrial dysfunction, inflammation, membrane signaling, and insulin resistance. Furthermore, different sizes of MPs impacted various organs differently, with all types and sizes of MPs interfered with the stomach across all exposure periods. The smaller MPs causing more produced disturbances in the small intestine, while mostly large-sizes of MPs affected on large intestine. Our findings indicate that MPs might pose health risks to the digestive system even at environmentally relevant doses. This underscores the need for increased awareness and further research into the health impacts of MP exposure.