Micro/Nanoplastics Alter Daphnia magna Life History by Disrupting Glucose Metabolism and Intestinal Structure

Microplastic pollution poses growing risks to aquatic zooplankton, yet its impact on Daphnia magna life history remains incompletely understood. This study explored the influences of micro/nanoplastics (MPs/NPs) on D. magna by exposing organisms to size- and concentration-varied microplastics, tracking microplastic distribution via fluorescence imaging. Results demonstrated significant microplastic-induced impairments in growth and reproduction. Gut microbiota analysis revealed microplastic-altered microbial communities, with functional prediction identifying disrupted glucose metabolism as a key driver of life-history changes. Intestinal structure observations further showed microplastic-accelerated aging. Collectively, our findings highlight that microplastic accumulation in D. magna disrupts gut microbiota and tissue integrity, ultimately impairing life-history traits. These alterations in growth and gut characteristics of D. magna may further propagate through the aquatic food web, potentially damaging the intestinal structure and function of plankton communities. Given the pivotal role of zooplankton in nutrient cycling and energy transfer, our findings underscore that microplastic-induced disruptions in key species like D. magna could threaten the stability and sustainability of aquatic ecosystems.