Approximately 60% of women in the United States experience a UTI, or acute cystitis, during their lifetime. Of these, 30% go on to have multiple recurrences.1 For women who suffer from frequent recurrences, effective preventive strategies are essential to free them from this disruptive illness. Unfortunately, the use of antibiotics for UTI prevention is becoming more problematic because resistance to commonly used agents is now widespread, infection caused by Clostridium difficile is increasingly common, and our appreciation of the importance of an undisturbed microbiome in health is growing. Therefore, investigations of antibiotic-sparing approaches to UTI prevention are of great interest to physicians and patients alike.