Yes, there are numerous clinical studies on Lactobacillus probiotic strains for vaginal health. Lactobacillus species are predominant in the healthy vaginal ecosystem. Lactobacillus Rhamnosus and Lactobacillus Acidophilus have shown to reduce vaginal pathogen through several mechanisms such as the production of lactic acid, hydrogen peroxide, and bacteriocin that inhibits the growth of pathogens causing bacterial vaginosis (BV) and other infections.
References:
1. Bertuccini L, Russo R, Iosi F, Superti F. Effects of Lactobacillus rhamnosus and Lactobacillus acidophilus on bacterial vaginal pathogens. Int J Immunopathol Pharmacol. 2017;30(2):163-167. doi:10.1177/0394632017697987
2. Homayouni A, Bastani P, Ziyadi S, et al. Effects of probiotics on the recurrence of bacterial vaginosis: a review. J Low Genit Tract Dis. 2014;18(1):79-86. doi:10.1097/LGT.0b013e31829156ec
3. Hanson L, VandeVusse L, Jermé M, Abad CL, Safdar N. Probiotics for Treatment and Prevention of Urogenital Infections in Women: A Systematic Review. J Midwifery Womens Health. 2016;61(3):339-355. doi:10.1111/jmwh.12472