Protective effects of dietary supplementation of Bacillus Subtilis MZ18 against the reproductive toxicity of zearalenone in pregnant rats.

The microbial detoxification method demonstrates significant potential for detoxifying feed contaminated with mycotoxins, but the application of degrading bacteria in mammals was rarely investigated. In this study, the effects of dietary zearalenone on the growth performance, reproductive performance, reproductive organs, hormone levels of rats and the toxicity alleviation of Bacillus subtilis MZ18 were studied. From gestation day 0-20, pregnant SD rats received either a normal diet or a diet supplemented with zearalenone at a dose of 20 mg/kg⋅BW, and with or without supplementation of Bacillus subtilis MZ18 culture. In addition to the negative effects on the growth performance of dietary zearalenone, we found that the ovarian weight was increased, the number of follicles and granulosa lutein cells in the corpus luteum was reduced, and the placental tissue exhibited an enlarged interstitial space and signs of stasis. Further analysis revealed a reduction in serum levels of LH, FSH, and E, followed by verification using quantitative RT-PCR analysis and Western blot analysis. Additionally, fetal weight and fetal brain weight were decreased, indicating that exposure to zearalenone during gestation has a negative impact on fetal development. As expected, our research revealed that dietary supplementation with MZ18 effectively mitigates reproductive toxicity caused by zearalenone exposure, including histopathological damage to reproductive organs, and disorders in reproductive hormone levels. The MZ18 treatment had no adverse effects on pregnant rats and fetal rats. The findings of this study provide a foundation for analyzing the mechanism of protective actions.