Analysis of vaginal and endometrial microbiota communities in infertile women with a history of repeated implantation failure

Abstract

Purpose To identify specific bacterial communities in vaginal and endometrial microbiotas as biomarkers of implantation failure by comprehensively analyzing their microbiotas using next‐generation sequencing. Methods We investigated α‐ and β‐diversities of vaginal and endometrial microbiotas using 16S rRNA gene sequencing and compared their profiles between 145 women with repeated implantation failure (RIF) and 21 controls who lacked the factors responsible for implantation failure with a high probability of being healthy and fertile to identify specific bacteria that induce implantation failure. Results The endometrial microbiotas had higher α‐diversities than did the vaginal microbiotas (P < .001). The microbiota profiles showed that vaginal and endometrial samples in RIF patients had significantly higher levels of 5 and 14 bacterial genera, respectively, than those in controls. Vaginal Lactobacillus rates in RIF patients were significantly lower at 76.4 ± 38.9% compared with those of the controls at 91.8 ± 22.7% (P = .018), but endometrial Lactobacillus rates did not significantly differ between the RIF patients and controls (56.2 ± 36.4% and 58.8 ± 37.0%, respectively, P = .79). Conclusions Impaired microbiota communities containing specific bacteria in both the endometrium and vagina were associated with implantation failure. The vaginal Lactobacillus rates, but not the endometrial, may be a biomarker for RIF.

The endometrial microbiota of women with or without a live birth within 12 months after a first failed IVF/ICSI cycle

“…Lactobacillus was the most relatively abundant genus in almost all endometrium samples in our study, which is consistent with several previous studies 3 , 5 – 8 , 28 – 30 . However, one previous study using endometrial tissue, obtained after hysterectomy, detected hardly any lactobacilli at all 31 .…”

The Endometrial Microbiome and Its Impact on Human Conception

“…Nonetheless, there were different bacterial compositions, and the RIF group exhibited significant enrichment of 14 genera—including Atopobium , Burkholderia , Delftia , Gardnerella , and Prevotella —but similar abundance of endometrial Lactobacillus spp. [ 11 ]. Lastly, greater levels of L. helveticus , Sneathia amnii , and the genus Prevotella were reported among patients with RIF, and higher numbers of L. iners , L. jensenii , and the genus Ralstonia were found in subjects without RIF [ 79 ].…”

“…For instance, uterine colonization is hypothesized to occur from gut, oral cavity, bloodstream, and vaginal ascension [ 3 , 5 ], but uterine seeding could potentially occur through assisted reproductive technology (ART) procedures and placement of contraceptive devices [ 6 , 7 ] as well as attachment of microorganisms to human spermatozoa [ 8 ]. Regardless of its origin, research consistently demonstrates that the uterine microbiome is highly diverse and scarcely populated compared with the lower genital tract [ 9 , 10 , 11 ], but its composition remains to be fully unraveled.…”

Recurrent implantation failure: A comprehensive summary from etiology to treatment

“…Patients with RIF presented higher microbial α-diversity than the control group ( 99 ). Meanwhile, vaginal Lactobacillus in patients with RIF was significantly decreased compared with healthy women, and the vaginal microbiota profiles in patients with RIF had significantly higher levels of five bacterial genera than in healthy women ( 102 ). Therefore, the number of vaginal Lactobacillus spp.…”