Recent advances in microplastics research: impacts on mammalian sperm and reproductive health

Formed via the physical, chemical, and biodegradation of plastic products, Microplastics (MPs) are plastic fragments smaller than 5 mm. As a notable contributor to environmental pollution, MPs have gained significant attention owing to their wide application and potential toxicity. MPs have been reported to accumulate in mammalian reproductive organs, adversely affecting male sperm quality, and pose a serious threat to male fertility. Therefore, it is important to understand how MPs exposure impacts sperm and the male reproductive system. This manuscript reviews the research progress of MPs exposure on sperm toxicity from three aspects: the effect of MPs on spermatogenesis and sperm quality, the ‘Trojan horse effect’ and cross-generational effect of MPs. The findings indicated a significant correlation between MPs exposure and reduced sperm quality reduction as well as abnormal spermatogenesis. Additionally, the study highlights the’ Trojan horse effect’ and cross-generation toxicity of MPs in mammals. This manuscript also reviews current treatment approaches for MPs exposure, providing a valuable theoretical foundation for future scientific research and clinical interventions. In summary, this review emphasizes that MPs can impair male reproductive health through mechanisms such as inflammatory responses, hormonal disruption, and sperm toxicity. By consolidating current evidence, this work lays a foundation for future research to further investigate the molecular pathways and long-term effects of MPs on male fertility.