Long-Term Exposure to Environmentally Realistic Doses of Starch-Based Microplastics Suggests Widespread Health Effects.

There is a growing consensus on addressing the global plastic pollution problem by advocating for bioplastics. While starch-based plastics are prevalent, the potential health implications of starch-based microplastics (SMPs) remain largely unexplored. This is particularly concerning given their potential for accidental ingestion and subsequent interference with blood glucose metabolism. Our research provides the first investigation into the distribution and adverse effects of long-term exposure to environmentally relevant doses of SMPs in female mice, approximately 14-81 particles per mouse per day. After three months of exposure, SMPs were found to infiltrate the liver, intestine, and ovarian tissues, causing microstructural lesions. Exposure to SMPs also resulted in elevated blood glucose levels, increased hepatic oxidative stress, and disrupted lipid metabolism. A multiomics analysis further uncovered abnormalities in gene expression and microbiota, as well as enriched pathways related to insulin regulation and circadian rhythms in the exposed mice. Our results indicate that prolonged exposure to environmentally relevant doses of SMPs can have widespread health effects in mice, potentially disrupting circadian rhythms by inducing insulin resistance. This suggests that the safety of bioplastics requires further evaluation before their large-scale application in food packages.