Alterations in urinary microbiota composition in children with overactive bladder: insights from 16S rRNA gene sequencing.

This study aimed to characterize the urinary microbiota profiles in pediatric patients with overactive bladder (OAB) compared to healthy controls, identify differentially enriched microbial taxa, and explore their associations with clinical symptoms and functional pathways. Urine samples were collected from 87 children (39 OAB patients, 48 controls) aged 5-14 years. Microbial DNA was extracted, and the V3-V4 regions of the 16 S rRNA gene were sequenced using the Illumina NovaSeq6000 platform. To delineate microbial community variations and functional associations, bioinformatics pipelines and statistical approaches-including permutational multivariate ANOVA (PERMANOVA), principal coordinates analysis (PCoA), linear discriminant analysis effect size (LEfSe), and Spearman's correlation-were applied to assess α/β-diversity, taxon-specific disparities, and clinical phenotype linkages in 16 S rRNA sequencing datasets. Clinical parameters, such as urinary urgency severity, nocturnal enuresis, and residual urine, were correlated with microbial composition. While no significant differences in α-diversity were observed between groups, β-diversity analysis revealed distinct clustering of microbial communities (ANOSIM, P = 0.001). OAB patients (OABs) exhibited enrichment in Proteobacteria, Gammaproteobacteria, Enterobacterales, Sphingomonas, and Escherichia-Shigella, whereas controls showed higher abundances of Clostridia, Bacteroidales, and Prevotella. Positive correlations were detected among Defluviitoga, Escherichia-Shigella, and Ligilactobacillus, while Defluviitoga negatively correlated with Bacteroides. Functional prediction highlighted OAB-associated upregulation of antibiotic resistance, biofilm formation, and bacterial secretion pathways. Subgroup analyses further linked severe OAB symptoms to elevated inflammatory taxa (e.g., Enterobacteriaceae) and residual urine to Gammaproteobacteria dominance. Pediatric OAB is associated with a dysbiotic urinary microbiota characterized by pro-inflammatory bacteria and altered metabolic functions. Specific microbial signatures, such as Escherichia-Shigella and Enterobacterales, may contribute to pathogenesis, while Prevotella and Clostridia in controls suggest protective roles. Specific microbial signatures associate with disease severity and possess functional capacities linked to inflammation, urothelial invasion, and immune evasion. Our findings underscore the urinary microbiome's contribution to pediatric OAB pathogenesis, suggesting promise for microbiome-informed diagnostic and therapeutic strategies.