The vaginal microbiota among the different status of human papillomavirus infection and bacterial vaginosis

Although human papillomavirus (HPV) infection plays a decisive role in causing tumors, its infection is insufficient for independently promoting cancer development and other co-factors facilitate the carcinogenic process. The objective of this study was to demonstrate the association between vaginal microbiota and high-risk human papillomavirus (HR-HPV) infection in women with and without bacterial vaginosis (BV). The study included 1015 women aged 21-64 who participated in cervical cancer screening in two areas of China from 2018 to 2019. Women were collected cervical exfoliated cell specimens and reproductive tract secretions samples for HR-HPV, BV and microbial composition testing. From the non-BV & HPV- group (414 HPV-negative women without BV) to the non-BV & HPV+ group (108 HPV-positive women without BV), to the BV & HPV-group (330 HPV-negative women with BV) and then to the BV & HPV+ group (163 HPV positive-women with BV), microbial diversity increased. The relative abundance of 12 genera, including Gardnerella, Prevotella, and Sneathia increased, while Lactobacillus declined. Correlation networks of these genera and host characteristics were disrupted in the non-BV & HPV+ group, and the network trended more disordered in the BV & HPV+ group. Besides, multiple HPV infection, certain HPV genotype infection and cervical intraepithelial neoplasia (CIN) status were associated with some microbes and higher microbial diversity. HPV shifted the composition and diversity of vaginal microbiota, and BV further reinforced the trend. The relative abundance of 12 genera increased and 1 genus decreased on account of BV and HPV infection, and some genera including Lactobacillus, Prevotella, and Sneathia were associated with some specific HPV genotypes infection and CIN.