子宫内膜癌是一种多因素疾病，炎症、代谢和潜在微生物因素参与疾病发病机制。迄今为止，子宫内膜癌微生物组的特征还很不清楚，并且由于缺乏适当的污染控制整合，研究常常高估了细菌生物量。关于子宫内膜癌中微生物微环境功能的证据也很缺乏。这项工作通过询问患有子宫内膜癌的女性生殖道和直肠中真实的、无污染的微生物特征以及微生物组在致癌过程中的机制作用来解决这一知识差距。在这里，我们对生殖道的不同区域（阴道、 61 名患者（37 名子宫内膜癌；24 名良性对照）的子宫颈、子宫内膜、输卵管和卵巢）和直肠。我们对 V1-V2 高变区进行 16S rRNA 基因测序，并对 16S rRNA 基因进行 qPCR 定性和定量评估微生物群落，并使用 3D 良性和子宫内膜癌类器官评估卷曲乳杆菌微生物产物的效果，发现在对子宫内膜细胞增殖和炎症进行初步分析后，子宫内膜癌患者体内的细胞因子被耗尽。我们发现，患有或未患有子宫内膜癌的女性的上生殖道中的微生物群在数量和成分上与背景污染物有明显区别。子宫内膜癌与宫颈阴道和直肠细菌负荷减少以及乳杆菌种类相对丰度（包括卷曲乳杆菌）的减少、细菌多样性增加以及下生殖道和子宫内膜中卟啉单胞菌、普雷沃氏菌、嗜胃杆菌和厌氧球菌的富集有关。用卷曲乳杆菌条件培养基治疗良性和恶性子宫内膜类器官，在高浓度下可发挥抗增殖作用，但对细胞因子和趋化因子谱的影响很小。我们的研究结果证明，一些女性的女性上生殖道含有可检测水平的细菌，其成分与子宫内膜癌有关。这是否是癌症病理生理学的原因或结果，以及这一发现的功能意义是什么，仍有待阐明，以指导未来的筛查工具和基于微生物组的治疗。视频摘要。© 2024。作者。

Endometrial cancer is a multifactorial disease with inflammatory, metabolic and potentially microbial cues involved in disease pathogenesis. The endometrial cancer microbiome has been poorly characterised so far and studies have often overestimated bacterial biomass due to lack of integration of appropriate contamination controls. There is also a scarcity of evidence on the functionality of microbial microenvironments in endometrial cancer. This work addresses that knowledge gap by interrogating the genuine, contamination-free microbial signatures in the female genital tract and rectum of women with endometrial cancer and the mechanistic role of microbiome on carcinogenic processes.Here we sampled different regions of the reproductive tract (vagina, cervix, endometrium, fallopian tubes and ovaries) and rectum of 61 patients (37 endometrial cancer; 24 benign controls). We performed 16S rRNA gene sequencing of the V1-V2 hypervariable regions and qPCR of the 16S rRNA gene to qualitatively and quantitatively assess microbial communities and used 3D benign and endometrial cancer organoids to evaluate the effect of microbial products of L. crispatus, which was found depleted in endometrial cancer patients following primary analysis, on endometrial cell proliferation and inflammation. We found that the upper genital tract of a subset of women with and without endometrial cancer harbour microbiota quantitatively and compositionally distinguishable from background contaminants. Endometrial cancer was associated with reduced cervicovaginal and rectal bacterial load together with depletion of Lactobacillus species relative abundance, including L. crispatus, increased bacterial diversity and enrichment of Porphyromonas, Prevotella, Peptoniphilus and Anaerococcus in the lower genital tract and endometrium. Treatment of benign and malignant endometrial organoids with L. crispatus conditioned media exerted an anti-proliferative effect at high concentrations but had minimal impact on cytokine and chemokine profiles.Our findings provide evidence that the upper female reproductive tract of some women contains detectable levels of bacteria, the composition of which is associated with endometrial cancer. Whether this is a cause or consequence of cancer pathophysiology and what is the functional significance of this finding remain to be elucidated to guide future screening tools and microbiome-based therapeutics. Video Abstract.© 2024. The Author(s).