Abstract
Abstract Background We investigated vaginal colonization using repetitive sequence PCR (repPCR) and 16S rRNA sequencing in a Phase 2b DBPC trial of a L. crispatus intravaginal suppository probiotic for prevention of rUTI in premenopausal women. Methods Twenty-four young women with a history of rUTI and current culture-confirmed symptomatic UTI were enrolled and treated (Visit 0), then randomized (Visit 1) to receive an intravaginal suppository containing L. crispatus CTV-05 (LACTIN-V®, Osel, Inc.) or placebo daily for 5 days, then once weekly for 2 months. Participants were followed up during the 2-month probiotic/placebo intervention (Visits 2 to 4; active intervention) and during 2 months following the intervention (Visits 5 and 6; post-intervention). At each visit, vaginal swabs were collected for repPCR to determine the presence or absence of the probiotic strain and the duration of its presence in the vagina and for 16S rRNA-based sequence analysis to determine relative abundance of any L. crispatus. Results LACTIN-V vaginal suppository induced selective and sustained colonization in the probiotic but not the placebo recipients, as follows. Pre-intervention: Probiotic lactobacillus strain, not found in vaginal specimens obtained from participants in either arm of study. Active intervention: (1) Probiotic lactobacillus strain, (a) Probiotic arm: 100% of participants positive at one or more visits and (b) Placebo arm: 0% of participants positive at any time. (2) L. crispatus relative abundance, (a) Probiotic arm: above 90%, all specimens, all visits and (b) Placebo arm: below 15%, all specimens, all visits. Post-intervention: (1) Probiotic lactobacillus strain, (a) Probiotic arm: 75% of participants positive at Visit 5, 58% at Visit 6 and (b) Placebo arm: 0% of participants positive at Visits 5 and 6. (2) L. crispatus relative abundance, (a) Probiotic arm: 70% to 100% and (b) Placebo arm: below 15%. Conclusion LACTIN-V L. crispatus vaginal probiotic achieved robust and persistent colonization throughout 2 months of weekly dosing and for 2 months after the last dose in most participants. Disclosures All authors: No reported disclosures.