Probiotic Therapy for UTIs: Are We Ready for Vaginal Supplements?

More than half of U.S. women will experience at least one urinary tract infection (UTI) during their lives. Because traditional antibiotic therapy for UTIs might add to the burgeoning problem of resistance, interest in probiotics has grown. Normal vaginal flora is dominated by hydrogen peroxide (H₂O₂⁺)-producing lactobacilli that displace competitive pathogenic bacteria (particularly Escherichia coli). Can an H₂O₂⁺-producing vaginal probiotic prevent recurrent UTIs?

In a trial that involved 100 women (median age, 21) with recurrent UTIs who were seen at the University of Washington student health center, investigators evaluated the efficacy of vaginal Lactobacillus crispatus (Lactin-V). Seven to 10 days after participants received standard a…