Research has found microplastics induce health effects in mice, including reproductive toxicity in male, pregnant mice, and their offspring, behavioral changes, and potentially increase insulin resistance. While these studies used microplastics made of fossil fuels (mainly polystyrene), microplastics made of bio-based feedstocks have received minimal attention so far; they are often promoted as one solution to address plastic pollution.
Jing Liu from Southeast University, Nanjing, China, and co-authors have now demonstrated that starch-based microplastics, blended with polylactic acid (PLA), can result in several health outcomes in mice, and this occurs at environmentally relevant concentrations. In their article published April 9, 2025, in the Journal of Agricultural and Food Chemistry, the authors describe that upon long-term exposure (three months), microplastics were present in the liver, intestines, and ovaries, where they led to structural damage. Microplastic exposure resulted in elevated blood glucose levels, leading to fat accumulation and increased oxidative stress in the liver. Furthermore, the authors made several observations (e.g., changes in fecal microbiota, gene expression) indicating disrupted insulin regulation and circadian rhythms.
Based on their findings, the scientists express concerns about bio-based microplastics and call for in-depth investigations on their potential health impacts. Their study adds to previously raised challenges of bio-based plastics, which include the presence of toxic chemicals.
Importantly, further research needs to verify the results of Liu and co-authors, since they used a small sample size. They exposed five female mice each to low doses (50 mg microplastics/kg food; approximately 16 particles per day), or high doses (50 mg microplastics/kg food; 82 particles per day) – levels which “closely approximate human dietary microplastic exposure levels.” After three months of exposure, the researchers used polarized light microscopy for analyzing the plastic particles in mouse tissues, as well as histopathological analysis, biochemical evaluation, hepatic transcriptomic analysis, and microbial community analysis to evaluate potential effects by comparing to the unexposed control group.
Reference
Liu, J. et al. (2025). “Long-Term Exposure to Environmentally Realistic Doses of Starch- Based Microplastics Suggests Widespread Health Effects.” Journal of Agricultural and Food Chemistry. DOI: 10.1021/acs.jafc.4c10855
Read more
Perkins, T. (May 13, 2025). “Starch-based bioplastic may be as toxic as petroleum-based plastic, study finds.” The Guardian
Other micro- and nanoplastic research published in April and May 2025
Ciornii, D. et al. (2025). “Interlaboratory Comparison Reveals State of the Art in Microplastic Detection and Quantification Methods.” Analytical Chemistry. DOI: 10.1021/acs.analchem.4c0540
Gosselink, I. F. et al. (2025). “Size- and polymer-dependent toxicity of amorphous environmentally relevant micro- and nanoplastics in human bronchial epithelial cells.” Microplastics and Nanoplastics . DOI: 10.1186/s43591-025-00126-9
Pan, W. et al. (2025). “Identification and analysis of microplastics in peritumoral and tumor tissues of colorectal cancer.” Scientific reports. DOI: 10.1038/s41598-025-98268-6
Sánchez-Piñero, J. et al. (2025). “Exploring the release of microplastics’ additives in the human digestive environment by an in vitro dialysis approach using simulated fluids.” Science of The Total Environment. DOI: 10.1016/j.scitotenv.2025.179333
Shen, R. et al. (2025). “Effects of polystyrene microparticles exposures on spermatogenic cell differentiation and reproductive endpoints in male mice.” Environmental Pollution. DOI: 10.1016/j.envpol.2025.126200
Vailionytė, A. et al. (2025). “In vitro effects of aged low-density polyethylene micro(nano)plastic particles on human airway epithelial cells.” Environmental Pollution. DOI: 10.1016/j.envpol.2025.126186
Zhang, L. et al. (2025). “Cross-platform detection of microplastics in human biological tissues: Comparing spectroscopic and chromatographic approaches.” Journal of Hazardous Materials. DOI: 10.1016/j.jhazmat.2025.138133
Zheng, J. et al. (2025). “In vivo and In vitro assessment of the retinal toxicity of polystyrene nanoplastics.” Environment International. DOI: 10.1016/j.envint.2025.109420
Zahir Arju, Z. B. et al. (2025). “Deep-learning enabled rapid and low-cost detection of microplastics in consumer products following on-site extraction and image processing.” Royal Society of Chemistry. DOI: 10.1039/d4ra07991d
This article was originally published by Lisa Zimmermann at the Food Packaging Forum.
