Lactobacillus species are widely recognized for their role in supporting vaginal health, and there is substantial scientific evidence to validate their use. The healthy human vagina is typically dominated by Lactobacillus species, such as L. crispatus, L. jensenii, L. gasseri, and L. iners. These beneficial bacteria help maintain a low pH environment (around 4.5) by producing lactic acid, which inhibits the growth of pathogens, including bacteria associated with bacterial vaginosis (BV) and yeast such as Candida albicans.

Numerous clinical studies and reviews have shown that oral or intravaginal administration of certain Lactobacillus strains can help restore and maintain a healthy vaginal microbiome, reduce the recurrence of BV, and support overall vaginal health. For example, a systematic review published in Clinical Microbiology Reviews (2016) and a Cochrane review (2018) both found moderate evidence supporting the use of probiotics containing Lactobacillus for managing and preventing BV.

However, the strength of the evidence varies depending on the specific strain, dose, and method of administration. Not all Lactobacillus species or strains are equally effective, and more research is needed to identify optimal formulations. Nonetheless, the use of Lactobacillus to support vaginal health is based on both a clear scientific rationale and clinical evidence, justifying its inclusion in probiotic supplements for this purpose.