The Endobiota Study: Comparison of Vaginal, Cervical and Gut Microbiota Between Women with Stage 3/4 Endometriosis and Healthy Controls

Abstract

Dysbiosis in the genital tract or gut microbiome can be associated with endometriosis. We sampled vaginal, cervical and gut microbiota from 14 women with histology proven stage 3/4 endometriosis and 14 healthy controls. The V3 and V4 regions of the 16S rRNA gene were amplified following the 16S Metagenomic Sequencing Library Preparation. Despite overall similar vaginal, cervical and intestinal microbiota composition between stage 3/4 endometriosis group and controls, we observed differences at genus level. The complete absence of Atopobium in the vaginal and cervical microbiota of the stage 3/4 endometriosis group was noteworthy. In the cervical microbiota, Gardnerella, Streptococcus, Escherichia, Shigella, and Ureoplasma, all of which contain potentially pathogenic species, were increased in stage 3/4 endometriosis. More women in the stage 3/4 endometriosis group had Shigella/Escherichia dominant stool microbiome. Further studies can clarify whether the association is causal, and whether dysbiosis leads to endometriosis or endometriosis leads to dysbiosis.

Figure 1

Principal Coordinates analysis showing the distribution of the vaginal, cervical and stool samples, based on Bray-Curtis dissimilarity matrices. Blue dots indicate control group (n = 14), red dots, stage 3–4 endometriosis group (n = 14).

Figure 2

Boxplots depicting the Shannon diversity index of the cervical (Cx), gut (G) and vaginal (V) microbiota in control (C) (n = 14) and endometriosis (E) (n = 14) groups. Boxes indicate the first and third quartiles, dash lines the upper and lower whiskers, crosses indicate the mean, and horizontal bold lines the median.

Figure 3

Sample graphs showing some of the genera which had different abundance between stage 3–4 endometriosis (n = 14) and controls (n = 14).

Figure 4

Most abundant taxa (at genus level) among healthy controls (n = 14) and women with stage 3–4 endometriosis (n = 14) in vaginal samples.

Figure 5

Most abundant taxa (at genus level) among healthy controls (n = 14) and women with stage 3–4 endometriosis (n = 14) in cervical samples.

Figure 6

Most abundant taxa (at genus level) among healthy controls (n = 14) and women with stage 3–4 endometriosis (n = 14) in stool samples.

Figure 7

Bacterial abundance in stool samples from controls (n = 14) and stage 3–4 endometriosis (n = 14) group. Increased Escherichia/Shigella abundance is observed in E2 and E4 who later required segmental colon resection due to bowel involvement.