Vaginal Colonization by Probiotic Lactobacillus crispatus CTV-05 Is Decreased by Sexual Activity and Endogenous Lactobacilli

BackgroundTwo potencies of gelatin capsules containing Lactobacillus crispatus CTV-05 were evaluated for safety and vaginal colonization in 90 young women MethodsSexually active females aged 14–21 years were randomized to receive either 106- or 108-cfu CTV-05 capsules inserted intravaginally twice daily for 3 days. At enrollment and at 4 weekly follow-up visits, behavioral and demographic information and quantitative vaginal cultures were collected. Lactobacillus species were identified by DNA hybridization, and the CTV-05 strain was discerned using repetitive-sequence polymerase chain reaction DNA fingerprinting ResultsOf the 90 participants, 87 returned for at least 2 follow-up visits. Of 40 participants who lacked L. crispatus colonization at enrollment, 36 (90%) were successfully colonized by CTV-05 at 1 or more follow-up visits, whereas only 24 (51%) of 47 participants colonized by L. crispatus at enrollment were positive for CTV-05 at follow-up (P