The role of vulvar, vaginal, and gut microbiota in the pathogenesis and clinical course of vulvar lichen sclerosus: a narrative review.

Vulvar lichen sclerosus (VLS) is a chronic disease of unclear aetiology, leading to progressive atrophic changes in the skin and mucous membranes of the anogenital region. The condition is associated with an increased risk of developing vulvar squamous cell carcinoma. Increasing evidence suggests that dysbiosis of the vulvar, vaginal and gut microbiota plays an important role in the pathogenesis of VLS. Patients with VLS show a reduced abundance of beneficial bacteria, mainly of the genus Lactobacillus, and an increase in potentially pathogenic microorganisms, including Prevotella, Enterobacter and Parvimonas. These changes correlate with symptom severity and immunological disturbances. Mendelian randomisation analyses suggest that selected taxa of the gut microbiota may have a protective function by modulating the inflammatory response. Further research is needed on the potential use of probiotics as an adjunct to VLS therapy.