Microplastics-perturbed gut microbiota triggered the testicular disorder in male mice: Via fecal microbiota transplantation

Microplastics (MPs), an emerging environmental pollutant, have been clarified to induce testicular disorder in mammals. And the current studies have delineated a correlation between gut microbiota and male reproduction. However, it's still unclear whether gut microbiota gets involved in MPs-induced reproductive toxicity. In this work, we constructed a mouse model drinking 5 μm polystyrene-MPs (PS-MPs) at the concentrations of 100 μg/L and 1000 μg/L for 90 days. Evident histological damage, spermatogenetic disorder and hormones synthesis inhibition were observed in PS-MPs exposed mice. With fecal microbiota transplantation (FMT) trial, the recipient mice exhibited gut microbial alteration, and the elevated abundance of Bacteroides and Prevotellaceae_UCG-001 were positively correlated with testicular disorder according to spearman correlation analysis. Mechanistically, increased proportion of pro-inflammatory bacteria may drive translocation of T helper 17 (Th17) cells, resulting in overproduced interleukin (IL)-17 A and downstream inflammatory response in both the mice exposed to PS-MPs and corresponding recipient mice. In summary, our findings revealed the critical role of gut microbiota in PS-MPs-induced reproductive toxicity, and tried to elucidate the underlying mechanism of gut microbial dysregulation-mediated IL-17 A signaling pathway. Furthermore, this study also provides the research basis for gut microbiota-targeted treatment of male infertility in the future.