Features of the Vaginal and Vestibular Microbioma in Patients With Vestibulodynia: A Case-Control Study.

OBJECTIVE: Our objective was to determine the role of vaginal and/or vestibular microbiota disturbance as an associated factor of symptom characteristic of provoked vestibulodynia (PVD). STUDY DESIGN: In an observational case-control study, the bacterial microbiomes in the vagina and vestibule from 20 women with PVD and 18 healthy controls were compared using a 16S rRNA gene-based molecular analysis. Clinical data were recorded through a 0- to 10-point visual analog scale related to dyspareunia and vulvovaginal pain/burning. RESULTS: Comparative assessment of the bacterial taxa (cutoff ≥15%) revealed 105 genera in the vaginal samples of PVD patients and 113 genera in the vestibular samples. Similarly, 120 genera were detected in the vaginal samples and 151 in the vestibular samples of the control group. Bacterial complexity was higher in the vestibular samples than in vaginal samples in both groups, without statistically significant differences. The following 3 dominant taxonomic units were found: Lactobacillus, Gardnerella, and Atopobium in PVD patients and Lactobacillus, Gardnerella, and Bifidobacterium in the control group. Lactobacillus gasseri was dominant only in women with PVD, showing a significant correlation with burning/pain intensity and dyspareunia severity (0.255 and 0.357, respectively, p < .001). CONCLUSIONS: Our data suggest that bacterial communities in vaginal discharge are an important contributor to the vestibular microbiota. Lactobacillus gasseri may be an element of vulnerability toward the development of vaginal dysbiosis. We can postulate its association as a potential etiologic organism in some individuals, either by itself or in some combination with other trigger factors.

The bacterial microbiome in paired vaginal and vestibular samples from women with vulvar vestibulitis syndrome.

Composition of the bacterial microbiome in the vagina and vestibule from 30 women with vulvar vestibulitis syndrome (VVS) and 15 healthy controls were compared by pyrosequencing 16S rRNA gene amplicons. Vaginal concentrations of interleukin (IL)-1ß were determined by ELISA. Questionnaires elicited clinical and symptom data. Eighteen genera were detected in vaginal samples, and 23 genera were identified in vestibule samples, from women with VVS. The genera at both sites and the mean number of genera in subjects with VVS were largely similar to those in control subjects. However, differences were noted including higher proportions of Streptococcus and Enterococcus in women with VVS. Furthermore, Lactobacillus iners was more frequently identified in women with VVS while L. crispatus was more frequent in the control women. The dominant bacterial genera in the vagina closely paralleled the dominant genera present in the corresponding vestibular sample in both groups, leading us to postulate that vaginal secretions are an important source of bacteria present on the vestibule. Vaginal IL-1ß levels were similar and varied depending on the dominant bacteria. We conclude in this pilot study that no major differences are apparent in the vagina and vestibule between women with or without VVS, except for an increased prevalence of Streptococcus and L. iners in some women with VVS.

Polymorphism in a gene coding for the inflammasome component NALP3 and recurrent vulvovaginal candidiasis in women with vulvar vestibulitis syndrome.

OBJECTIVE: Patients with vulvar vestibulitis syndrome (VVS) and control subjects were tested for a polymorphism in the gene coding for the NALP3 component of inflammasomes, cytoplasmic structures regulating interleukin (IL)-1beta production. STUDY DESIGN: DNA from 143 women with VVS and 182 control women were tested for a length polymorphism in intron 4 of the gene (CIAS1) that codes for NALP3. Vestibular tissue was examined for NALP3 expression. Whole blood cultures were tested for Candida albicans-induced IL-1beta production. RESULTS: The allele 12 frequency was higher in control subjects than in the patients with VVS (P = .02). Among patients with VVS and a self-reported history of recurrent vulvovaginal candidiasis (RVVC), the allele 7 frequency was 43.9% as compared with 30.8% in patients with no history of RVVC and 26.9% in control women (P = .035 vs other patients and .001 vs control subjects). NALP3 was identified in vestibular tissue. C albicans-induced IL-1beta production was reduced in samples from women with the 7,7 genotype (P = .030). CONCLUSION: Polymorphism in the CIAS1 gene may play a central role in the triggering of VVS in a subset of patients.