Vaginal microbiota among young women and its relation to and HPV infection

Human papillomavirus (HPV) infection is one of the most common sexually transmitted diseases. Even though HPV vaccination has contributed enormously to reduce HPV infection and related cancers, there are still many HPV subtypes that do not cover in vaccination and more intervention for HPV infection is urgently needed. Changes in vaginal microbiota with the absence of Lactobacilli and increased microbial diversity has shown to facilitate sexually transmitted infections in some countries. To define the HPV infection associated microbial community in a Nordic country, we analyzed the microbial community composition of Swedish young women and its association to HPV infection status as well as 27 HPV subtypes. 16S rRNA gene sequencing was used to characterize the vaginal microbiota from vaginal swab samples collected from a youth clinic (age: 14~ 22; n=156), and a gynecological clinic and a maternal health care centers (age: 23~29; n=126). Microbiota alpha diversity analysis revealed a significantly increased diversity in the HPV infected group compared to HPV negative group, especially from young girls infected by oncogenic HPV subtypes. The vaginal microbiota among HPV infected women was characterized by higher levels of bacteria including bacterial vaginosis-associated bacterium (BVAB), Megasphaera, Prevotella, and Gardnerella. Our results suggest HPV infection, including both high-risk and low-risk subtypes, is associated with increased vaginal microbiota diversities regardless of age and vaccination status. Multi-types HPV infection is related to increased microbial diversity. In addition, bacteria that significantly related to HPV infection could be used as potential biomarkers and treatment targets.