(108) The Vaginal and Vulvar Microbiomes of Post-menopausal Women with Lichen Sclerosus
Authors: Taylor O , Birse K , Hill D , Myers A , Marino J , Burgener A , Pope R , Farr Zuend C 
Published: May 2023

Abstract

Introduction
Lichen sclerosus is a chronic, inflammatory disorder of the genital and extragenital skin that can lead to sexual dysfunction. The possible causes of this disorder include genetic predisposition, chronic irritation, infection and autoimmunity. Post-menopausal women are at higher risk for Lichen sclerosus. The vaginal microbiome is important for reproductive health and is known to shift after menopause to a Lactobacillus-depleted community due to changes in estrogen levels. However, little is known about the role of the vaginal and vulvar microbiome in Lichen sclerosus and its pathogenesis.

Objective
Here, we describe and compare microbial taxa between matching vaginal and vulvar samples collected from post-menopausal women with Lichen sclerosus.

Methods
Matching vaginal and vulvar swabs were collected from 27 women with Lichen sclerosus. Genomic DNA was extracted from swab eluates using the QIAGEN DNeasy Blood and Tissue kit and PCR amplification was performed on the V3-V4 regions of the 16s rRNA gene using 745R and 341F customized primers. 16S rRNA sequencing was performed using the Illumina MiSeq platform. Data was analyzed using the Mothur pipeline with alignment using SILVA, and ribosomal database project (RDP) for taxonomic classification. Sequencing analysis and plots were performed with R programming software packages: reshape2, ggplot, dplyr, compositions, and vegan. Statistical tests were performed on proportional and CLR-transformed data.

Results
Of the 27 vaginal samples, 51.9% (n=14) were polymicrobial, 22.2% (n=6) were Gardnerella co-dominant, 14.8% (n=4) were Lactobacillus dominant, 3.7% (n=1) was Atopobium co-dominant, 3.7% (n=1) was Corynebacterium dominant, and 3.7% (n=1) was Staphylococcus dominant. Of the 27 matching vulvar samples, 55.6% (n=15) were polymicrobial, 14.8% (n=4) Staphylococcus co-dominant, 7.4% (n=2) were Gardnerella co-dominant, 7.4% (n=2) Atopobium co-dominant, 7.4% (n=2) Lactobacillus dominant, and 7.4% (n=2) Lactobacillus/Bifidobacterium co-dominant. Principal coordinate analysis demonstrated that samples grouped based on the participant they were collected from suggesting similar beta diversity between vaginal and vulvar microbiomes within the same woman (Bray-Curtis distances, p =0.001, r2=0.833, perMANOVA). However, there were a number of bacteria (n=14) that significantly differed between the vaginal and vulvar compartments including Actinomyes, Corynebacterium, Campylobacter, Peptoniphilus, Staphylococcus, Ezakiella, Finegoldia, Porphyromonas, and Actinotignum which were increased in vulvar microbiome whereas Enhydrobacter, Lactobacillus, Micrococcus, Granulicatella and Bacillus were increased in the vaginal microbiome (p&lt;0.05, paired t-test). Vulvar samples were also significantly more diverse than matching vaginal samples (Shannon’s H index, paired t-test, p=0.042).

Conclusions
Women with Lichen sclerosus have diverse, non-Lactobacillus dominant vaginal and vulvar microbiomes, which are considered less optimal for reproductive health. Understanding the role of these bacteria in Lichen sclerosus pathogenesis will be an important future investigation.

Disclosure
No