增塑剂DEHP通过肠道菌群改变而诱导雌性生殖毒性

Plasticizer DEHP induces female reproductive toxicity through changes in intestinal flora

目的观察增塑剂邻苯二甲酸二(2-乙基己基)酯[di-(2-ethylhexyl)phthalate,DEHP]对SD大鼠肠道菌群组成及卵巢功能的影响,并初步探讨肠道菌群改变与雌性生殖毒性的可能关系。方法将30只SD大鼠随机分为5组,每组6只,分别为玉米油对照组及5、50、500、2500 mg/(kg·d)DEHP剂量组,连续灌胃14天,测定并比较实验后各组大鼠血清抗苗勒氏管激素(anti-müllerian hormone,AMH)水平及卵巢质量指数变化,同时,对大鼠粪便进行16S rRNA扩增子测序分析。结果DEHP暴露后,对照组及5、50、500、2500 mg/(kg·d)剂量组AMH水平分别为(5.41±0.39)、(4.98±0.44)、(4.99±0.12)、(4.30±0.51)、(3.91±0.23)ng/mL,卵巢质量指数分别为(0.058±0.002)、(0.056±0.001)、(0.052±0.002)、(0.049±0.002)、(0.045±0.003)g/g,与对照组比较,除5 mg/(kg·d)组外,其余剂量组AMH水平及卵巢质量指数均有显著降低(P<0.05),血清AMH水平与DEHP暴露剂量呈负相关(P<0.01),大鼠卵巢质量指数呈剂量依赖性下降;DEHP暴露后大鼠肠道菌群中厚壁菌门的相对丰度减少,拟杆菌门的相对丰度增加,厚壁菌门/拟杆菌门的比例显著降低(P<0.05);厚壁菌门为DEHP剂量组的特征菌群,其中肠杆菌科、肠杆菌目、乳酸杆菌属、瘤胃球菌科和梭状芽孢杆菌科,对组间差异均有显著影响(均P<0.05)。结论DEHP暴露后,大鼠肠道菌群结构改变,卵巢功能下降,DEHP可能通过改变肠道菌群结构诱导雌性生殖毒性。

Objective To observe the effect of plasticizer di-(2-ethylhexyl)phthalate(DEHP)on intestinal flora composition and ovarian function in SD rats,and to preliminarily explore the possible relationship between changes in intestinal flora and female reproductive toxicity.Methods Totally 30 SD rats were randomly divided into 5 groups,with 6 rats in each group,namely the corn oil control group and 5,50,500 and 2500 mg/(kg·d)DEHP dosage groups.The rats were gavaged continuously for 14 days.The changes of serum anti-millerian hormone(AMH)level and ovarian mass index in each group were compared after the experiment.Meanwhile,16S rRNA amplicon sequencing analysis was performed on rat feces.Results After DEHP exposure,the AMH levels in the control group and the 5,50,500,and 2500 mg/(kg·d)dose groups were(5.41±0.39),(4.98±0.44),(4.99±0.12),(4.30±0.51)and(3.91±0.23)ng/mL,respectively,and the ovarian mass index was(0.058±0.002),(0.056±0.001),(0.052±0.002),(0.049±0.002)and(0.045±0.003)g/g.Compared with the control group,AMH levels and ovarian mass index were significantly reduced in all dose groups except the 5 mg/(kg•d)group(all P<0.05).Serum AMH levels were negatively correlated with the dose of DEHP exposure dose(P<0.01).Ovarian mass index of rats decreased in a dose-dependent manner after DEHP exposure.After DEHP exposure,the relative abundance of Firmicutes in the intestinal flora of rats decreased,while the relative abundance of Bacteroides increased,and the ratio of Firmicutes/Bacteroides decreased significantly(P<0.05).Firmicutes was the characteristic flora of DEHP dosage group,among which Enterobacteriaceae,Enterobacteriales,Lactobacillus,Ruminococcaceae and Lachnospiraceaeall had significant effects on the differences between groups(all P<0.05).Conclusion After exposure to DEHP,the structure of intestinal flora in rats changed and the ovarian function decreased.DEHP may induce female reproductive toxicity by changing the structure of intestinal flora.