Polystyrene nanoparticles (PSNPs) are a newly emerging pollutant in the natural environment. However, due to the lack of sufficient toxicological studies in mammals, the potential effects of PSNPs on human health remain largely undefined. Therefore, in this study, young mice aged four weeks old were subjected to oral administration of 0, 0.2, 1, or 10 mg/kg PSNPs for 30 days. Our results demonstrated for the first time that oral exposure to PSNPs affected the expressions of mucus secretion-related genes and altered the community composition of intestinal microbiota, although this treatment did not cause behavioral impairments in young mice. No significant alterations in inflammatory or oxidative stress-related indicators were observed in the liver, lung, intestine, cortex or serum of PSNPs-treated animals. Moreover, exposure to PSNPs did not cause pathological changes in the liver, lung, or cortex tissues. Notably, although oral administration of PSNPs did not produce obvious toxic effects in the major organs of young mice, the possible toxicity of PSNPs remains unresolved and it may depend on the dose, exposure route and species. The potential hazardous effects of PSNPs still need to be systematically assessed, especially for children who are susceptible to exposure to nanoparticles.

聚苯乙烯纳米粒子 (PSNPs) 是自然环境中一种新兴的污染物。然而，由于缺乏足够的哺乳动物毒理学研究，PSNPs 对人类健康的潜在影响在很大程度上仍未确定。因此，在本研究中，4 周龄的幼鼠口服 0、0.2、1 或 10 mg/kg PSNPs 30 天。我们的结果首次证明，口服暴露于 PSNP 会影响粘液分泌相关基因的表达并改变肠道微生物群的群落组成，尽管这种治疗不会导致幼鼠的行为障碍。在 PSNPs 治疗的动物的肝脏、肺、肠、皮层或血清中没有观察到炎症或氧化应激相关指标的显着变化。而且，暴露于 PSNPs 不会引起肝脏、肺或皮质组织的病理变化。值得注意的是，虽然口服 PSNPs 对幼鼠的主要器官没有产生明显的毒性作用，但 PSNPs 的可能毒性仍未得到解决，这可能取决于剂量、暴露途径和物种。PSNPs 的潜在危险影响仍然需要系统地评估，特别是对于容易接触纳米颗粒的儿童。