Composition of the vaginal microbiota in relation to cervical intraepithelial lesions.

Objective: This study aimed to investigate the relationship between cervical intraepithelial neoplasia associated with human papillomavirus (HPV) infection and the vaginal microbiome.

Materials and methods: In this study, the vaginal microbiota profile was compared among three groups of women: those with HPV infection and no cervical intraepithelial neoplasia (NILM, n=35), those with low-grade squamous intraepithelial lesions (LSIL, n=28), and those with high-grade squamous intraepithelial lesions (HSIL, n=24). Vaginal bacterial diversity was analyzed by deep sequencing of the V3-4 region of the barcoded 16S rRNA gene using the Illumina MiSeq platform, considering alpha diversity, beta diversity, and taxon classifications. Statistical significance was set at p<0.05.

Results: In the analyses performed using Chao1, Inverse Simpson, Shannon, and Observed indices, statistically significant differences were found among the groups in terms of all indices (p<0.05). Among groups, beta diversity did not show any notable differences. According to the "Linear Discriminant Analysis Effect Size" analysis, the taxa enriched in the HSIL group were Roseburia inulinivorans (p=0.0308), Micromonosporaceae family (p=0.0331), and Pirellula genus and species, (Planctomycetes), (p=0.0165); the taxa enriched in the LSIL group were Actinobaculum genus and species (p=0.0183). Lactobacillus helveticus and Faecalibacterium prausnitzii were more abundant in the NILM group, while Prevotella copri, Akkermansia muciniphila, and Fusobacterium species were more abundant in the LSIL and HSIL groups.

Conclusion: Our findings indicate that variations in the severity of cervical lesions are associated with notable alterations in vaginal microbiota composition. Further research is required to conclude which contribute to the formation of the cervical lesion and which are a consequence, among those that cause changes in the vaginal microbiota, of the lesion.