UTERINE MICROBIOME IN HEALTHY FERTILE WOMEN AND IN CASE OF ENDOMETRIUM PATHOLOGY IN MULTIPLE FAILURES OF IN-VITRO-FERTILIZATION PROGRAMS

Abstract

Background: Thanks to new diagnostic technologies, it is of no doubt that the uterus is no longer considered to be sterile. A disturbed microbiome of endometrium can be a significant reason for preterm birth, infertility, the recurrence of pregnancy loss, and repeated implantation failures in in-vitro-fertilization programs. Aim: Study the endometrial microbiome features in healthy fertile women and in women with multiple in-vitro-fertilization failures. Methods: To assess the differences in the endometrial microbiota of 20 women with infertility and experiencing multiple unsuccessful attempts of in-vitro-fertilization and 15 fertile, healthy women, endometrial microbiome was studied using an NGS of 16S rRNA. Results and Discussion: Lactobacillus (29.4%), Comamonas (16.8%), and Mesorhizobium (6.0%) were the most abundant genera in group of healthy fertile patients, and Lactobacillus (33.3%), Ralstonia (7.9%) and Pediococcus (4.8%) were most abundant in the group of infertile patients. The mean relative abundance of Lactobacillus did not significantly differ between groups and comprised 33.3% in the group of infertile women and 29.4% in healthy fertile women. A considerably higher mean relative abundance of bacteria of the genus Brevundimonas and Ralstonia was recorded in the group of infertile women. The fertile women had a statistically significantly higher mean relative abundance of Acidovorax, Brevibacillus, Caulobacter, Comamonas, Delftia, Distigma, Pseudomonas, Schlegelella, and Thermus. Conclusions: The presented data confirm that endometrium is not a sterile tissue despite long-standing concepts concerning its sterility. Lactobacillus are dominant genera; however, there is no absolute dominance of Lactobacillus over 90%. The mean relative abundance of Lactobacillus in the uterine microbiome in fertile patients and patients with multiple in-vitro-fertilization failures did not differ.