Is Vulvodynia Associated with an Altered Vaginal Microbiota? A Systematic Review

Introduction Vulvodynia is defined as vulvar pain of at least 3 months' duration, without clear identifiable cause, which may have potential associated factors. It can have a significant impact on women's quality of life due to a combination of physical pain, emotional distress, and limited treatment options. Despite affecting a considerable number of women worldwide, the causes and underlying mechanisms of vulvodynia remain poorly understood. Given the recognized association of the vaginal microbiota with various gynecologic disorders, there has been growing interest in exploring the potential role of the vaginal microbiota in the etiology of vulvodynia. This systematic review aims to evaluate the current literature on the association between the vaginal microbiota and vulvodynia. Material and Methods A systematic search of multiple databases, including PubMed, Scopus, Web of Science, Cochrane Library, and Ovid MEDLINE, was conducted to identify relevant peer-reviewed studies up to May 12, 2023. The following search terms were used across these databases: "vulvodynia,""vestibulodynia,""vulvar vestibulitis,""microbiome,""microbiota,"and "flora."Results A total of 8 case-control studies were included, the quality of which was assessed using the Newcastle-Ottawa Scale. Data extraction and synthesis were performed using a standardized protocol. In most studies, no major differences were found between the vaginal bacterial composition of women with vulvodynia and that of controls. No specific bacterial taxa were consistently associated with vulvodynia. The relationship between vaginal microbiota diversity and vulvodynia remains to be fully understood. Conclusions The role of vaginal microbiota in vulvodynia, if any, remains unclear. Because of the cross-sectional nature of the included studies, it is not possible to make any causal inferences. Further research, using larger and more diverse study populations and advanced sequencing techniques, is necessary to gain a better understanding of the potential relationship between the vaginal microbiota and vulvodynia.