Microplastics (MPs) are pervasive environmental contaminants, resulting in unavoidable human exposure. This study identified MPs in follicular fluid and investigated the specific MPs and mechanisms that adversely affect oocytes. MPs in the follicular fluid of 44 infertile women undergoing assisted reproductive technology were measured using Raman microspectroscopy. Differential metabolites in follicular fluid were analyzed via untargeted metabolomics. Female mice were exposed to polyethylene (PE) to validate human findings. MPs, particularly PE, exhibited the highest detection rate (86.4 %) in human follicular fluid and showed a negative correlation with fertilization rates (r = -0.407, P = 0.007). Elevated PE levels altered metabolites primarily involved in metabolic pathways, ferroptosis, and ovarian steroidogenesis. In mice, PE exposure significantly reduced the number of retrieved oocytes (31.5 vs. 36.3, P < 0.05) and fertilization rate (70.8 % vs. 85.2 %, P < 0.001), while increasing the proportion of poor-quality oocytes (28.2 % vs. 16.5 %, P < 0.001) and reactive oxygen species (ROS) production compared to controls. RNA sequencing indicated significant upregulation of inflammation-related genes (Il10ra, Il1a, Il33, Tnfaip8l2, and Tnfrsf1b) in the PE-exposed group. In conclusion, PE exposure impairs oocyte quality possibly by disrupting follicular fluid metabolism, elevating inflammation-related gene expression, and increasing ROS production in oocytes.

Microplastics (MPs) are becoming one of the most serious environmental threats worldwide. They have been shown to induce male reproductive toxicity in animal studies. However, evidence of their adverse effects on male reproductive health in human is still lacking. In this study, we evaluated the presence of MPs in human semen and explored their associations with semen quality. A total of 45 semen samples from men attending a fertility center were collected. MPs in the semen samples were analyzed by laser direct infrared (LD-IR) spectroscopy. MPs were found in 34 out of 45 semen samples, with an average abundance of 17.0 (42.0) particles/g. The size of MPs ranged from 20.3 μm to 189.7 μm and the majority (57.8%) were smaller than 50 μm. A total of 15 distinct MPs polymers were identified, and polyethylene (PET) accounted for 35.9% of the total amount of MPs, followed by butadiene rubber (BR, 26.4%) and chlorinated polyethylene (CPE, 12.2%). Analysis of the association of MP exposure with semen quality showed that participants exposed to PET MPs experienced a reduction in sperm progressive motility (20.6% ± 12.8% vs. 34.9% ± 15.9%, p = 0.056). However, no significant association was found between MP exposure and sperm concentration or total sperm count. Our findings confirmed the presence of MPs in human semen and suggested that MP exposure might have adverse impacts on male reproductive health. However, further large-scale studies are needed to confirm these findings.

Background: Polycystic ovary syndrome (PCOS) is characterized by excess androgens, ovulatory dysfunction, and polycystic ovaries. The mechanisms underlying ovulatory and metabolic disorders in PCOS remain elusive, hampering therapeutic development. Enhanced metabolic health correlates with increased microbiota gene content and microbial diversity. We aimed to explore the impact of gut microbiota and serum steroids on PCOS regulation associated with androgen excess.Methods: The fecal samples of patients with hyperandrogenic PCOS (n = 14) and control group with PCOS (n = 14) were analyzed by 16S rRNA gene sequencing. The peripheral venous blood of all subjects was collected to detect serum hormones. The association between gut microbiota and serum hormones was analyzed with the R language.Results: Our findings reveal that the hyperandrogenic PCOS group exhibits lower richness and diversity of gut microbiota compared to the control group. Characteristic genera in PCOS patients with hyperandrogenism include Bifidobacterium, Enterobacteriaceae_unclassified, Streptococcus, Saccharimonadaceae, Enterococcus, and Eubacterium_nodatum_group. Five hormones, including 5β-androsterone, deoxycorticosterone, corticosterone, 11-dehydrocorticosterone, and cortexolone, emerge as potential serum biomarkers for identifying patients with hyperandrogenic-PCOS (HA-PCOS). Furthermore, a lower vitamin D3 level may act as a susceptibility factor, suggesting that vitamin D3 supplementation could serve as a potential intervention for PCOS with hyperandrogenism.Conclusion: Specific fecal microbiota and serum steroids may be used as characteristic markers for clinical diagnosis of hyperandrogenic-PCOS. This research enhances our understanding of the intricate interplay among hormones, gut microbiota, and hyperandrogenemia in patients with PCOS.

Manual semen evaluation methods are subjective and time-consuming. In this study, a deep learning algorithmic framework was designed to enable non-invasive multidimensional morphological analysis of live sperm in motion, improve current clinical sperm morphology testing methods, and significantly contribute to the advancement of assisted reproductive technologies. We improved the FairMOT tracking algorithm by incorporating the distance and angle of the same sperm head movement in adjacent frames, as well as the head target detection frame IOU value, into the cost function of the Hungarian matching algorithm. For sperm morphology, we used the BlendMask segmentation method to segment individual sperm. SegNet was used to separate the head, midpiece, and principal piece comments from each sperm. Experienced in vivo sperm physicians confirmed a morphological accuracy percentage of 90.82%. A total of 1272 samples were collected from multiple tertiary hospitals for validation of the system, which were also evaluated by physicians. The results of our system were highly consistent with those of manual microscopy. This study realized the automated detection of progressive motility and morphology of sperm simultaneously, which is crucial for selection of morphologically normal and motile sperm for intracytoplasmic sperm injection.

Introduction: Microplastics and nanoplastics are prevalent environmental contaminants. Recent reports indicate that polystyrene nanoparticles may adversely impact male reproductive health. This study aims to examine the effects of polystyrene exposure on sperm metabolism and the development of pre-implantation embryos.Methods: In this study, male C57BL/6 mice were orally gavage-administered polystyrene nanoplastics (60 nm, 20 mg/kg/day) for 35 days to assess their impact on male reproduction and early embryonic development. Experiments included testicular transcriptome analysis, sperm metabolomics, sperm motility and fertilization assays, embryonic ROS detection, and RNA sequencing of 2-cell embryos, revealing the adverse effects of polystyrene exposure on sperm metabolism and embryo development.Results: The results revealed that oral gavage of polystyrene to male mice induced a pronounced immune-inflammatory response in testicular tissue, reduced sperm motility, and significantly lowered the fertilization rate. Notably, sperm from treated mice exhibited substantial metabolic disruptions, affecting key pathways, including glycerophospholipid biosynthesis and DNA repair. After fertilization, embryos at the 2-cell stage suffered damage in apoptotic and DNA repair pathways, subsequently impairing early embryo development.Discussion: In conclusion, this study demonstrated that the oral gavage administration of polystyrene nanoplastics to male mice significantly affects male reproductive function, resulting in abnormalities in early embryonic development and alterations in associated gene expression profiles. These findings offer essential scientific insights for future research into sperm-mediated transgenerational effects and their impact on early embryonic development.