Modulation effect of vaginal mucosal microflora and susceptibility to Neisseria gonorrhoeae infections: a systematic review and meta-analysis

Objective The vaginal microbiota may modulate susceptibility to Neisseria gonorrhea (NG) infections. The objective of this meta-analysis was to evaluate the association between these NG infections and the vaginal microbiota. Method A systematic review and meta-analysis was conducted to investigate the correlation of vaginal microbiota and NG risk. Primary sources of the reviewed studies were from inception through December 2018. Vaginal mucosa microflora were dichotomized into high- Lactobacillus vaginal microbiota and low- Lactobacillus vaginal microbiota (LL-VMB), using either Nugent score, Amsel’s criteria, presence of clue cells or 16S rRNA gene sequencing. Results A total of 8 studies qualified for inclusion in this meta-analysis. LL-VMB could be regarded as worse prognostic factor, and the pooled OR was 1.33 (95% CI 1.02, 1.73; P = 0.04, I 2 = 44%). LL-VMB was associated with a significantly higher susceptibility of NG. Trend for the sensitive analysis was consistence with the primary outcome. Significant publication bias was not detected by the funnel plot. Conclusion In conclusion, the systematic review and meta-analysis has demonstrated that LL-VMB was significantly associated with a high NG susceptibility.