Characterization of the vaginal microbiota in Italian women with endometriosis. Preliminary study

Purpose This cross-sectional study aims to assess the interplay between the vaginal microbiota and endometriosis. Methods 123 consecutive Italian fertile women, aged between 20 and 40 years old, were enrolled during a routine gynecological consultation; 24 were diagnosed with endometriosis and 99 did not complain of any gynecological disease. All women underwent a vaginal swab for the evaluation of the composition and diversity of vaginal microbiota by means of 16 s rDNA metagenomic sequencing. Results Compared to women with no gynecological disease, the vaginal microbiota in women with endometriosis showed a similar abundance of Lactobacillus spp.; however, a statistically significant lower abundance in the genera Pseudomonas (p < 0.01), Bifidobacterium (p < 0.05), Novispirillum (p < 0.0000001) and Sphingomonas (p < 0.0000001), and a statistically significant increase in the abundance of the genera Escherichia (p < 0.00001), Megasphaera (p < 0.00001), and Sneathia (p < 0.0001) were observed. Conclusions There is a complex interplay between vaginal microbiota composition and endometriosis, showing a distinct microbial signature in the bacterial genera usually found in dysbiosis.