Oral administration of Lactobacillus crispatus M247 to papillomavirus-infected women: results of a preliminary, uncontrolled, open trial

BACKGROUND: Vaginal microbiotas can be clustered into five different possible categories (CST I to V), according to their bacterial dominance. In CST I. the dominance of Lactobacillus crispatus seems to correlate with better vaginal health and with a lower incidence of sine causa infertility. pretenn delivery, bacterial vaginosis, and viral (including human papillomavirus; HPV) infection. According to the same method of classifying the vaginal microbiome, CST IV (non-Lactobacillus-dominated) demonstrates a higher incidence of disorders. METHODS: In an open, non-controlled study, we enrolled 35 HPV-positive women who mostly (N.=24) demonstrated CST IV status, with the other individuals categorized as having either CST III (N.=10) or CST II (N.=1) microbiotas. RESULTS: After 90 days of oral treatment with a probiotic (L. crispatus M247) we observed a reduction of approximately 70% in HPV positivity and a significant change in CST status with 94% of women now classified as CST I. CONCLUSIONS: Despite the limitations of our study, it is the first demonstration that it is possible to intervene orally with an L. crispatus probiotic to bring about a change in CST status and, in parallel, increased HPV clearance.