Evidence Hub

Microbiome in women with endometriosis and the in vitro effects of Lactobacillus reuteri on human endometrium

Jae Hoon Lee, Gee Soo Jung, Kyungmin Kim, Hyemin Park, Yunjeong Park, In-Jung Lee, Min Jung Lee, Ji-Ho Lee et al.

Microbiology spectrum, 2026

41 participants

Abstract

ABSTRACT Endometriosis (EMS) is a chronic inflammatory disorder affecting ~10% of reproductive-age women, with increasing evidence implicating the microbiome in its pathogenesis through immunomodulation and estrogen metabolism. This study investigated microbiome composition in the vagina, endometrium, and peritoneal fluid (PF) of women with and without EMS and further assessed the effects of Lactobacillus reuteri (L. reuteri) on endometrial (EM) cells in vitro. Samples from 41 patients were analyzed using 16S rRNA gene sequencing, targeting the V3–V4 regions. Western blotting, ELISA, and LC-MS/MS were employed to evaluate protein expression and estrogen metabolism during EM–L. reuteri co-culture with or without estradiol-17-glucuronide (E2G). Microbiome analysis revealed no significant differences in alpha or beta diversity between EMS and controls across all compartments. However, LEfSe analysis identified several taxa with differential abundance, with L. reuteri consistently altered in both vagina and EM. Across the menstrual cycle, EM and vaginal microbiomes were stable, whereas PF microbiota showed phase-dependent variation involving 60 genera and 76 species. In vitro, L. reuteri alone did not alter endometriosis-related proteins, but in the presence of E2G, it reduced BAX/Bcl-2 ratios and increased p-NF-κB, suggesting anti-apoptotic and pro-inflammatory shifts. Progesterone receptor α/β expression decreased, while estrogen receptor levels remained unchanged. L. reuteri…

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free