Lactobacillus salivarius is a probiotic bacterium commonly found in the human oral cavity, gastrointestinal tract, and, to a lesser extent, the urogenital tract. Its use for urinary system support is based on emerging scientific evidence, although the body of research remains limited and is not yet definitive.

Several small-scale clinical and in vitro studies have investigated the ability of L. salivarius to inhibit uropathogenic bacteria, such as Escherichia coli, which are commonly responsible for urinary tract infections (UTIs). The proposed mechanism involves competitive exclusion of pathogens, production of bacteriocins, and acidification of the urogenital environment, which can hinder pathogen growth. Some research has indicated that L. salivarius can adhere to uroepithelial cells and may reduce the risk of recurrent UTIs, especially in women. However, most interventions and clinical trials for urinary health have historically focused on other Lactobacillus species, such as L. rhamnosus and L. reuteri, with L. salivarius representing a newer focus.

In summary, while there is some scientific rationale and early evidence supporting the use of Lactobacillus salivarius for urinary system health, particularly in terms of pathogen inhibition and microbiome modulation, the evidence base is still limited. More robust clinical trials are needed to confirm its efficacy and establish clear guidelines for use.