Lactobacillus plantarum is a probiotic bacterium commonly found in fermented foods and used as a supplement for gastrointestinal and urogenital health. There is some scientific investigation into its possible role in supporting or preventing bladder infections (urinary tract infections, UTIs), though the evidence is not robust and should be considered preliminary.

The rationale behind using L. plantarum for bladder infections is its ability to help restore and maintain healthy vaginal and urinary microbiota, thus potentially inhibiting the growth of uropathogenic bacteria such as Escherichia coli. Some in vitro and animal studies indicate that certain strains of L. plantarum can adhere to urothelial cells and produce substances that inhibit pathogens. A few small human studies and reviews have looked at probiotics (often blends including L. plantarum) for UTI prevention, with mixed results and generally low certainty.

Overall, while there is biological plausibility and some early supportive evidence, robust clinical trials specifically confirming the efficacy of L. plantarum for treating or preventing bladder infections are lacking. Current scientific support is limited (rated 2/5), and its use is not yet standard clinical practice for UTIs.