Transcriptomic and Metabolomic Analyses Reveal Intestinal Lipid Metabolic Disturbance in Loaches Co-Exposed to Polystyrene Nanoplastics and Imidacloprid

Abstract

Simple Summary Polystyrene nanoplastics and the insecticide imidacloprid can occur together in freshwater. We examined the biological effects of their co-exposure in loaches. Fish were exposed for 21 days to either contaminant alone or to imidacloprid combined with three concentrations of polystyrene nanoplastics. Co-exposure was associated with lower survival, reduced antioxidant capacity, enhanced inflammatory responses, and greater injury in the gills, intestine, and liver. Intestinal transcriptomic and metabolomic analyses further revealed disturbances in digestive and lipid-metabolic processes. Quantitative PCR confirmed treatment-associated changes in five lipid-related genes. These findings indicate that the presence of polystyrene nanoplastics may enhance IMI-related adverse effects under the tested conditions and that disruption of intestinal lipid homeostasis is an important component of the co-exposure response.