Molecular and Pathological Characterization of Cervicovaginal Specimens Evince Significant Protection Against HPV Infections, Bacterial Vaginosis, and Epithelial Cell Abnormalities by Lactobacillus species

Background: Bacterial vaginosis (BV) results in dysbiosis in the vaginal microbiome and facilitates secondary human papilloma virus (HPV) infections, which can cause cervical abnormalities. The effects of Lactobacilli on BV-HPV infections and cervicovaginal pathology were investigated. Method. Electronic molecular and cytology laboratory results, and demographic records of 19,105 females screened for BV, HPV, and cervical cancer between August 2021 and April 2023 were collected. After data cleaning and reorganization, 15, 607 sample results were used. The data was subjected to epidemiological, statistical, and machine learning analyses to identify patterns, correlations, associations, and interactive effects of age, State, Lactobacilli, BV-associated pathogens, high-risk HPV (hrHPV) genotypes, BV, and cervical cytology. Results: The final dataset comprised of data from anonymized females (n = 15541, 99.57%), males (n = 13, 0.08%) and unknown gender (n = 53, 0.34%) between 14 and 95 years from 32 States and Washington D.C. Most samples were BV positive (n = 8282, 53.07%) and/or NILM (n = 11749) followed by 14.29% ASCUS (n = 2231), 7.14% LSIL (n = 1115), 1.04% RCC (n = 163), 0.53% HSIL (n = 82), 0.39% ASC-H (n = 61), and 0.16% AGC (n = 25). HPV-positive samples had higher BV pathogens and BV-positive diagnosis (between 51.90% and 68.60%) than BV-negative diagnosis. Lactobacillus gasseri (79.75%), Lactobacillus jensenii (82.68%), Lactobacillus crispatus (90.91%) were mostly found in BV-negative and NILM specimens. BV and ECA outcomes were significantly associated with age and State. Statistical, correlation, and machine learning models predictively confirmed these findings. Conclusion: L. crispatus, followed by L. gasseri and L. jensenii, significantly maintains a healthy cervicovaginal microbiome by inhibiting harmful bacterial pathogens and high-risk HPV subtypes; L. iners have an opposing or neutral effect.