Lactobacillus crispatus Capsules: Single-Use Safety Study in the Macaca nemestrina Model

In Brief Background Lactobacillus crispatus is a part of the normal vaginal microflora of humans. Goal The goal of this study was to assess whether a capsule containing an H2O2-producing strain of L crispatus (CTV-05) would alter the vaginal microflora and/or epithelial tissues when applied intravaginally in the pig-tailed macaque model. Study Design Ten sexually mature female Macaca nemestrina were assessed at baseline for quantitative vaginal microbiology and vaginal pH and with colposcopy. One capsule containing 108 colony forming units of desiccated L crispatus CTV-05 was inserted into the vaginal fornix of each animal. Vaginal assessments were repeated on days 1 and 2 after capsule insertion. The L crispatus CTV-05 strain was identified with use of a DNA fingerprinting method. Results Before product use, four of 10 animals had detectable levels of H2O2-producing lactobacilli. L crispatus CTV-05 was detected in 1 of 10 animals on day 1 and in 3 of 10 animals on day 2 following insertion of the capsule. There were no tissue changes observed by colposcopy. Vaginal pH decreased in two animals colonized by CTV-05, from 7.0 at baseline to 4.5 ± 0.5 on days 1 and 2 after product use. Conclusions A single intravaginal application of capsules containing 108L crispatus CTV-05 resulted in vaginal colonization in three of 10 animals 2 days after use. The absence of colposcopic changes in the vagina/cervical tissues indicates that L crispatus capsules are well tolerated. Intravaginal application of capsules containing Lactobacillus crispatus was well tolerated in the monkey model.