Nutritional bioactives for preventing recurrent urinary tract infections in children: microbiome-mediated mechanisms and clinical implications.

Recurrent urinary tract infections in children represent a common clinical challenge associated with repeated antibiotic exposure and rising antimicrobial resistance. These limitations have intensified interest in non-antibiotic preventive strategies, particularly nutritional bioactives capable of modulating host-microbe interactions. This review provides a clinically oriented synthesis of current evidence on dietary and nutraceutical interventions for the prevention of recurrent pediatric urinary tract infections. Particular attention is given to the limited availability of high-quality pediatric-specific evidence and the heterogeneity of current clinical data. It focuses on cranberry-derived type A proanthocyanidins, probiotics, selected micronutrients and D-mannose. Key mechanistic pathways are also highlighted, including inhibition of uropathogen adhesion, microbiome-mediated biotransformation of bioactives into anti-inflammatory metabolites, and modulation of host immune and epithelial responses within the gut-bladder axis. Available evidence suggests that cranberry products standardized to deliver approximately 36 mg/day of type A proanthocyanidins may reduce recurrence risk, whereas probiotics and vitamins A, C, and D may provide adjunctive benefits through microbiome modulation and enhancement of innate immune responses. However, substantial heterogeneity in study design, variability in formulations and dosing, and the limited availability of high-quality pediatric randomized trials remain important limitations. Building on current evidence, we propose a pragmatic multimodal framework for non-antibiotic prevention in children that integrates nutritional strategies with clinical risk stratification and individualized care, with particular attention to bioavailability, dose standardization and pediatric-specific factors such as age-related microbiome maturation. Future research should prioritize biomarker-driven endpoints, microbiome-informed stratification and adequately powered pediatric studies to define responders and optimize personalized prevention strategies.