Cranberry and Other Non-Antibiotic Approaches for the Prevention of Recurrent Urinary Tract Infections

Urinary tract infection (UTI) is one of the most common bacterial infections worldwide, especially among women. It is defined by the presence of clinical signs and symptoms involving the genitourinary tract, together with a significant bacterial load in the urine, typically ≥10²–10³ colony-forming units per milliliter. UTIs may involve the bladder (cystitis), kidney parenchyma (pyelonephritis), or prostate gland (prostatitis). Recurrent UTIs are common, affecting up to one-third of women after a first episode, and are defined as two or more infections within six months or three or more within one year For decades, low-dose daily or post-coital antimicrobial prophylaxis has been the cornerstone of preventing recurrent UTIs. However, concerns about antimicrobial resistance and adverse effects have driven interest in non-antibiotic alternatives such as probiotics, vaccines, oligosaccharide inhibitors of bacterial adhesion, immunoreactive Escherichia coli extracts, local estrogen therapy, and cranberry products. Cranberry, long investigated as a prophylactic agent, inhibits adhesion of P- and type I-fimbriated uropathogenic E. coli to the uroepithelium. Evidence suggests that proanthocyanidins (PACs) are the principal active compounds. Clinical findings remain inconsistent due to heterogeneity in product standardization, dosing, and trial design. Meta-analyses show a modest (~35%) reduction in recurrence among young and middle-aged women, with uncertain benefit in other populations. High dropout rates, gastrointestinal intolerance, excess caloric intake from juices, and potential drug interactions limit long-term adherence.While cranberry remains a promising adjunct in UTI prophylaxis, current data do not support its routine clinical use. Further well-designed, standardized clinical trials are necessary.