Exposure to 30 mg/kg/d of microplastics alone significantly increased blood glucose, glucose tolerance, and insulin resistance.Exposure of high-fat-diet mice to polystyrene microplastics significantly exacerbates oxidative stress, glucose tolerance, and insulin resistance and induces liver and pancreas damage.Polystyrene microplastics exacerbate type II diabetes by an underlying mechanism in part related to AKT/GSPK3β phosphorylation (associated with ROS). The gene discussed is AKT1; the disease is type 2 diabetes mellitus.