These findings suggest that gut-associated butyrate disturbance contributes to PS-NP-induced steroidogenic dysfunction, with a NaB-responsive EGR1-Cyp11a1 regulatory relationship implicated in Leydig cells.
Oral exposure to 100 nm polystyrene nanoplastics impaired intestinal barrier integrity and testicular steroidogenesis in male ICR mice.
Fecal microbiota transplantation from PS-NP-exposed donors partially reproduced the intestinal and steroidogenic abnormalities in antibiotic-pretreated recipient mice.
Untargeted metabolomics showed an FDR-significant decrease in relative testicular butanoic acid levels after PS-NP exposure.
Serum butyrate was decreased in PS-NP-exposed mice and in recipients of microbiota from exposed donors.
In vivo sodium butyrate supplementation partially improved reproductive and steroidogenesis-related outcomes in PS-NP-exposed mice.
Exploratory analyses and validation experiments implicated a NaB-responsive EGR1-Cyp11a1 regulatory relationship in Leydig cells.
The authors conclude that gut-associated butyrate disturbance contributes to PS-NP-induced steroidogenic dysfunction.
This study in mice examined how tiny plastic particles (polystyrene nanoplastics, 100 nanometers across) swallowed over 28 days might harm male reproductive health. The mice that ate the particles showed damage to the gut lining and reduced function of the testes' hormone-producing machinery (steroidogenesis). The researchers found evidence that the gut plays a role. When gut microbes from exposed mice were transferred into other mice whose own microbes had been cleared with antibiotics, those mice partly developed the same gut and testis problems. Exposed mice, and the mice receiving their microbes, had lower blood levels of butyrate, a compound made by gut bacteria, and the testes of exposed mice had less of the related chemical butanoic acid. Giving exposed mice sodium butyrate partly improved their reproductive and hormone-related measures.</br>Cell experiments and exploratory analyses also pointed to a gene regulator called EGR1 and a hormone-making enzyme gene, Cyp11a1, in testicular Leydig cells as part of the pathway. This research suggests that nanoplastics may affect male fertility partly by disturbing gut microbial products such as butyrate. These are findings in mice, the improvements from butyrate were only partial, and the EGR1 link was exploratory, so the results do not by themselves show the same effects occur in people.
Wang Y, Feng L, Yuan J, Yuan C, Khan E, Qin K, et al.. (2026). Oral Exposure to Polystyrene Nanoplastics Disrupts Gut-Testis Metabolic Homeostasis and EGR1-Associated Steroidogenic Regulation in Male Mice.. Journal of agricultural and food chemistry. https://doi.org/10.1021/acs.jafc.6c10448