Design: Cross sectional

Setting: Tertiary academic medical center

Patients or Participants: Samples were collected from patients with chronic pelvic pain and pathology-confirmed endometriosis (N=35), patients with chronic pelvic pain without endometriosis (N=23) and surgical control patients (N=19). Patients with endometriosis but no chronic pelvic pain were excluded (N=4).

Interventions: N/A

Measurements and Main Results: 16S rRNA sequencing was performed to profile the gut and vaginal microbiomes. CVL samples were collected, and a panel of soluble immune mediators were quantified by multiplex analysis. Statistical analysis was performed with SAS, R, MicrobiomeAnalyst, MetaboAnalyst, and Qiime2. Women with CPP, CPP-Endo, and surgical controls were found to have statistically significant differences in alpha-diversity at the species level in the gut microbiome. Within the CPP-Endo group, patients with peritoneal endometriosis implants showed taxonomic differences in vaginal microbial composition compared to patients without endometriosis and those with ovarian endometriosis. It was noted that patients with co-occurring abnormal uterine bleeding (AUB), despite disease groupings, had taxonomic differences in both gut and vaginal microbiomes. Global analysis of the immune profiles from CVLs revealed significant overlap between CPP and CPP-Endo compared to controls.

Conclusion: Analysis of the microbiome supports the association of gut and vaginal dysbiosis in women with CPP and CPP-Endo, though the clinical significance of observed differences needs to be investigated further. Patients with peritoneal endometriosis showed taxonomic differences compared to those with ovarian endometriosis or no endometriosis, suggesting vaginal microbiome variation based on site. AUB was also noted to demonstrate changes in microbial composition, so further study is needed to understand the effects of co-occurring conditions. Analysis of CVL immunoproteomics is ongoing.