Salivary microbiota changes and assists the diagnosis of cervical dysplasia

Objectives: Oral microbiota has been related to several diseases including cancers. Here, we performed oral microbiota analysis from saliva samples collected from participants with and without cervical dysplasia, and from patients before and after treatments. Their salivary microbiota has also been compared with participants that visit for dental examination.Methods: In total 47 participants visited Karolinska University hospital, Sweden for checking dysplasia and treatment, together with 20 healthy volunteers for regular dental examination are included. The vaginal HPV infection, the cytology, and the histology identification of dysplasia stages were obtained for the 47 hospital visitors and questionnaire on the life style were investigated for all 67 participants. The salivary microbiota were characterized on extracted DNA using bacterial 16S ribosomal RNA (16S rRNA) gene sequencing of the V3-V4 regions. Based on the histology identification and treatment, the salivary microbiota data from the 47 patients were divided into groups with and without dysplasia, groups within normal limits (WNL) vs. low-grade squamous intraepithelial lesion (LSIL) vs. high-grade squamous intraepithelial lesion (HSIL), and groups pre-treatment and post-treatment.Results: A significantly increased microbiota diversity and richness were identified in the salivary microbiota of control group that visit for dental examination than participants visited hospital for dysplasia checking. Significantly reduced Haemophlius and Alloprevotella and increased Campylobacter and Stomatobaculum in salivary microbiota were observed when compare the salivary microbiota of dental examination control group with the dysplasia examination groups. Haemophlius and Alloprevotella demonstrated a high specificity to predict dysplasia. Moreover, three salivary microbiota types were detected, with type 1 been observed mainly in the dental examination control group and type 2 and type 3 mainly in the vaginal examination groups.Further evaluation on vaginal examination participants revealed that the significantly differential microbiota was identified between groups with and without dysplasia and between pre-treatment and after-treatment groups. Actinomyces was identified as the main significantly increased genus in dysplasia patients when compared with the patients without dysplasia, while the Stomatobaculum was identified as the main increased genus in pre-treatment patients compared to post-treatment patients. Actinomyces was detected to be related to an increased immune signaling pathway. Notably, Actinomyces assisted the specificity and sensitively together with vaginal HPV and cytology in distinguishing dysplasia patients from patients without dysplasia.By analyzing the contribution of lifestyle of the 67 participants to the salivary microbiota, smoking habit was significantly affected the oral microbiota except age. Further investigation demonstrated that Actinomyces was the main significantly increased genus in among smokers than participants who never smoked.Conclusions: This study provides supportive evidence on the correlation of salivary microbiota and cervical dysplasia, and suggests smoking influence the salivary microbiota and correlates with an increased the risk of cervical dysplasia. Further investigation is needed in considering salivary microbiota, e.g. Actinomyces as a predict factor and potential targets for smoking related diseases and cervical dysplasia.