Microbiome of the lower genital tract in Chinese women with endometriosis by 16s-rRNA sequencing technique: a pilot study Original paper

What Was Studied?

This study investigated the microbiome composition of the lower genital tract in Chinese women with endometriosis using 16S rRNA sequencing. Researchers aimed to explore differences in microbial diversity and specific bacterial populations between women diagnosed with endometriosis and healthy controls. The analysis focused on samples collected from the cervical canal, posterior fornix, and uterine cavity to identify distinct microbial profiles and potential biomarkers associated with endometriosis and adenomyosis. A total of 68 participants were included in the study, with 134 samples collected and processed for microbiome analysis.

Who Was Studied?

The study involved 68 women aged 18 to 45, divided into groups: 20 with endometriosis (EM), 19 with adenomyosis (AM), 7 with both adenomyosis and endometriosis (AMEM), and 36 healthy controls (CT). Samples were collected from the cervical canal, posterior fornix, and uterine cavity using sterile techniques to minimize contamination. Participants were excluded if they had bacterial vaginosis (BV), pelvic inflammatory disease, recent antibiotic use, or other infections that might influence microbial composition. This design allowed for a focused investigation of microbiota differences in the lower genital tract specifically related to endometriosis and adenomyosis.

What Were the Most Important Findings

The study found that Lactobacillus remained the predominant genus in the lower genital tract across all groups, reflecting typical vaginal flora. However, significant microbial shifts were observed in women with adenomyosis-endometriosis (AMEM). At the genus level, Atopobium was notably enriched in AMEM patients, representing the most significant microbial difference. While Lactobacillus dominance persisted, AMEM patients exhibited a substantial increase in Coriobacteriaceae and Campylobacteriaceae, indicating a divergence from healthy microbial communities. The AMEM group also displayed elevated levels of Coriobacteriales at the order level, further distinguishing it from other disease groups and controls. Interestingly, LeFSe analysis did not identify specific biomarkers between the cervical canal and posterior fornix, but PICRUSt analysis suggested functional differences, particularly in ribosome biogenesis and two-component system regulation, which may influence immune modulation in endometriosis. The findings suggest that Atopobium may contribute to the pathogenesis of endometriosis through immune disruption, potentially mediated by increased levels of IL-1β, which has been linked to chronic inflammation. The consistent presence of Coriobacteriaceae and Campylobacteriaceae in AMEM further supports a hypothesis of localized dysbiosis contributing to inflammatory processes.

What Are the Greatest Implications of This Study?

This study provides evidence of distinct microbiome alterations in the lower genital tract of women with endometriosis, particularly among those with concurrent adenomyosis. The enrichment of Atopobium and Coriobacteriaceae suggests that specific microbial communities may influence inflammatory pathways and disease progression in endometriosis. The identification of ribosome biogenesis and two-component system regulation as significant functional pathways indicates that microbial-induced immune modulation could play a role in lesion persistence and symptom severity. These findings propose Atopobium as a potential microbial biomarker for adenomyosis-endometriosis and highlight the possibility of targeted microbiome-based therapies to disrupt pathological microbial communities. The study underscores the importance of microbial profiling as a non-invasive diagnostic tool for identifying endometriosis-related dysbiosis, potentially leading to earlier detection and intervention.