The human endometrium is a dynamic entity that plays a pivotal role in mediating the complex interplay between the mother and developing embryo. Endometrial disruption can lead to pregnancy loss, impacting both maternal physical and psychological health. Recent research suggests that the endometrial microbiota may play a role in this, although the exact mechanisms are still being explored, aided by recent technological advancements and our growing understanding of host immune responses. Suboptimal or dysbiotic vaginal microbiota, characterized by increased microbial diversity and reduced Lactobacillus dominance, has been associated with various adverse reproductive events, including miscarriage. However, the mechanisms linking the lower reproductive tract microbiota with pregnancy loss remain unclear. Recent observational studies implicate a potential microbial continuum between the vaginal and endometrial niche in patients with pregnancy loss; however, transcervical sampling of the low biomass endometrium is highly prone to cross-contamination, which is often not controlled for. In this review, we explore emerging evidence supporting the theory that a dysbiotic endometrial microbiota may modulate key inflammatory pathways required for successful embryo implantation and pregnancy development. We also highlight that a greater understanding of the endometrial microbiota, its relationship with the local endometrial microenvironment, and potential interventions remain a focus for future research.

中文翻译：

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子宫内膜微生物群和早期妊娠丢失

人类子宫内膜是一个动态实体，在调节母亲和发育中胚胎之间复杂的相互作用中发挥着关键作用。子宫内膜破坏可能导致流产，影响母亲的身心健康。最近的研究表明，子宫内膜微生物群可能在其中发挥了作用，尽管在最近的技术进步和我们对宿主免疫反应日益了解的帮助下，确切的机制仍在探索中。次优或失调的阴道微生物群，其特征是微生物多样性增加和乳杆菌优势减少，与各种不良生殖事件（包括流产）有关。然而，下生殖道微生物群与流产之间的联系机制仍不清楚。最近的观察性研究表明，流产患者的阴道和子宫内膜生态位之间存在潜在的微生物连续体。然而，低生物量子宫内膜的经宫颈取样很容易发生交叉污染，而这种污染往往不受控制。在这篇综述中，我们探讨了支持以下理论的新证据：失调的子宫内膜微生物群可能调节成功胚胎植入和妊娠发育所需的关键炎症途径。我们还强调，更好地了解子宫内膜微生物群、其与局部子宫内膜微环境的关系以及潜在的干预措施仍然是未来研究的重点。