The maternal gut microbiota can influence and be affected by the substantial physiological changes taking place during the periparturition period. However, little information is known about the changes in the maternal gut microbiota and hormonal variations during this period in nonmodel organisms. Tibetan antelope (Pantholops hodgsonii) provide a unique system to address this issue because their summer migration cycle is synchronized with the periparturition period. Here, we used fecal microbiota as a proxy of gut microbiota. We characterized fecal microbial community of female migratory Tibetan antelope in the late pregnancy and postpartum periods using 16S rRNA gene sequencing and quantified fecal glucocorticoids (GCs) and triiodothyronine (T3) metabolite concentrations through enzyme immunoassays to identify the associations between maternal gut microbiota and physiological changes related with reproduction. We found that the fecal microbiota of Tibetan antelope was dominated by Firmicutes and Bacteroidetes. The microbial composition was significantly altered during the transition from late pregnancy to the postpartum period. Fecal T3 concentration was significantly higher in the postpartum period compared to late pregnancy, whereas GC metabolite concentration did not significantly differ between two reproductive states. We identified six genera (Anaerofustis, Bacteroides, Coprococcus_2, Ruminiclostridium_5, Ruminococcaceae_UCG-007, and Tyzzerella) that were significantly associated with reproductive states. We also found two genera (Christensenellaceae_R-7_group and Rikenellaceae_RC9_gut_group) significantly associated with GC metabolite concentration and two genera (Agathobacter and Papillibacter) significantly associated with T3 metabolite concentration, though these correlations were weak with coefficient values ranging from - 0.007 to 0.03. Our results indicate that many members of the gut microbiota are associated with the physiological changes in the transition from late pregnancy to the postpartum period, likely reflecting the metabolic and immune system dynamics during the periparturition period. This study highlights the importance of integrating microbiota, hormones and migration pattern to study the reproductive health of wildlife. By establishing a baseline of the physiological changes during the migration/periparturition period, we can have a better understanding of the impacts of increasing human activities on the Tibetan Plateau on the reproductive health of Tibetan antelope.

中文翻译：

---

围产期藏羚羊（Pantholops hodgsonii）母体肠道菌群的变化

母体肠道微生物群可以影响围产期发生的重大生理变化并受其影响。然而，关于非模式生物在此期间母体肠道微生物群的变化和激素变化的信息知之甚少。藏羚羊 (Pantholops hodgsonii) 提供了一个独特的系统来解决这个问题，因为它们的夏季迁徙周期与围产期同步。在这里，我们使用粪便微生物群作为肠道微生物群的代表。我们使用 16S rRNA 基因测序表征了雌性迁徙藏羚羊在妊娠晚期和产后的粪便微生物群落，并通过酶免疫测定法量化粪便糖皮质激素 (GCs) 和三碘甲状腺原氨酸 (T3) 代谢物浓度，以确定母体肠道微生物群与生理变化之间的关联与繁殖有关。我们发现藏羚羊的粪便微生物群以厚壁菌门和拟杆菌门为主。在从妊娠晚期到产后期的过渡期间，微生物组成发生了显着变化。与妊娠晚期相比，产后粪便中的 T3 浓度显着更高，而两种生殖状态之间的 GC 代谢物浓度没有显着差异。我们确定了六个属（Anaerofustis、拟杆菌、粪球菌_2、瘤胃梭菌_5、瘤胃球菌科_UCG-007 和 Tyzzerella）与生殖状态显着相关。我们还发现两个属（Christensenellaceae_R-7_group 和 Rikenellaceae_RC9_gut_group）与 GC 代谢物浓度显着相关，两个属（Agathobacter 和 Papillibacter）与 T3 代谢物浓度显着相关，尽管这些相关性很弱，系数值范围为 - 0.007 到 0.03。我们的研究结果表明，肠道微生物群的许多成员与从妊娠晚期到产后过渡期间的生理变化有关，这可能反映了围产期的代谢和免疫系统动态。这项研究强调了整合微生物群的重要性，激素和迁移模式来研究野生动物的生殖健康。通过建立迁徙/围产期生理变化的基线，我们可以更好地了解青藏高原人类活动增加对藏羚羊生殖健康的影响。