Adjunctive Oral Probiotic Therapy for Preventing Recurrent Urinary Tract Infections in Women: A Randomized Clinical Trial

Abstract

Background: Recurrent urinary tract infections (rUTIs) remain a common and clinically challenging condition among women, leading to repeated antibiotic exposure, increasing antimicrobial resistance, and impaired quality of life. Conventional preventive strategies often fail to prevent recurrence, highlighting the need for effective non-antibiotic adjunctive therapies. This study evaluated the effectiveness of adjunctive oral probiotic therapy in Libyan women with recurrent urinary tract infections.Methods: An open-label, randomized, parallel-group clinical trial was conducted at a tertiary urology clinic in Libya between September 2022 and September 2025. A total of 365 women aged 18–60 years with recurrent urinary tract infections were randomly assigned to receive either conventional therapy alone (n = 182) or conventional therapy plus a daily oral probiotic containing Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 (5 × 10⁹ CFU each) for 3–6 months (n = 183). Participants were followed for 12 months. The primary outcome was recurrence of symptomatic urinary tract infections, while secondary outcomes included lower urinary tract symptoms, pain, quality of life, and adverse events.Results: A total of 345 participants completed the study (169 conventional therapy and 176 probiotic therapy). Women receiving probiotics experienced significantly fewer recurrent urinary tract infections than those receiving conventional therapy alone. Overall, 63.1% of women in the probiotic group experienced ≤1 UTI during follow-up compared with 14.8% in the conventional group, whereas recurrent infections (≥4 episodes/year) occurred in 6.8% and 49.1% of participants, respectively (χ² = 96.84, p < 0.001). Probiotic therapy also resulted in significantly greater resolution of burning symptoms (61.4% vs. 26.0%), pain reduction (74.4% vs. 34.3%), and improvement in quality of life (72.7% vs. 31.4%) (all p < 0.001). No serious adverse events related to probiotic supplementation were reported.Conclusion: Adjunctive oral supplementation with Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 significantly reduced recurrent urinary tract infections and improved urinary symptoms and quality of life among Libyan women. These findings support probiotic therapy as a safe and effective complementary strategy for the prevention of recurrent urinary tract infections.