P0605Preventing UTIs in Women with IBD: Early Results of a Randomized Double-Blind Trial of D-Mannose

Abstract Background Urinary tract infections (UTIs) are a frequent extraintestinal complication in women with inflammatory bowel disease (IBD), especially in those receiving biologic therapy. Recurrent UTIs often require repeated antibiotics, worsen dysbiosis and may lead to interruption of IBD treatments. D-mannose has shown preventive efficacy against UTIs in non-IBD patients, but evidence in immunosuppressed individuals is limited. We present preliminary data from the ongoing double-blind study, initiated in March 2025. Methods This is a prospective, randomized, double-blind, multicenter trial conducted across two IBD referral centers. Eligible participants were adult women with CD or UC diagnosed for ≥12 months, receiving biologic therapy, and with a documented history of recurrent cystitis. Patients were randomized to D-mannose or placebo for 6 months (8 days/month). Clinical evaluation, biochemical testing and monthly urinalysis with urine culture were performed. The primary endpoint was the occurrence of UTI confirmed by urine culture. Results A total of 32 women were enrolled, and 26 completed the 6-month course (15 D-mannose; 11 placebo). Median age was 54 years (35–78). IBD characteristics: 12 Crohn’s disease (46%) and 14 ulcerative colitis (54%). CD patients showed predominantly ileal or ileocolonic disease, with several stricturing or fistolizing phenotypes; UC patients presented pancolitis or left-sided colitis. Five Crohn’s patients had prior surgery, mostly ileal resections for stricturing or penetrating disease. Disease activity at enrolment was mainly mild to moderate, with calprotectin typically 80–250 µg/g and mild endoscopic involvement. Biologic therapies included 6 infliximab, 4 adalimumab, 4 ustekinumab, and 11 vedolizumab. Across 26 completers, 9 UTIs were documented: 3/15 (20%) in the D-mannose group vs 6/11 (54.5%) in placebo, corresponding to a relative risk reduction of 63%, absolute reduction of 34.5%, NNT = 3. Infections in the D-mannose group occurred early and were due to Klebsiella pneumoniae or Enterococcus faecium; one case involved intermittent catheterization. Placebo-group infections were mainly E. coli, including early episodes in infliximab-treated patients. No adverse events or treatment-related reactions occurred; tolerability was excellent. Conclusion These preliminary findings suggest that D-mannose prophylaxis may significantly reduce UTI incidence in women with IBD, particularly for E. coli infections, while demonstrating optimal safety and compatibility with biologic treatment. The study is ongoing, and final results will clarify the preventive role of D-mannose in this high-risk population. Conflict of interest: Dr. Palmisano, Chiara Maria: No conflict of interest Contaldo, Antonella: No conflict of interest Suriano, Valeria: No conflict of interest Pranzo, Giuseppe Carlo: No conflict of interest Principi, Maria Beatrice: No conflict of interest