Exploring urogenital microbiome differences in children with and without overactive bladder: first approach

INTRODUCTION: Overactive bladder (OAB) affects up to 10% of healthy children, with poorly understood mechanisms. Recent adult data implicate the urogenital microbiome in lower urinary tract symptoms. This pilot study explored the relationship between the urogenital microbiome and OAB in children. METHODS: A prospective cohort study was conducted in children aged 5-11 years with OAB and age matched controls (2020-2023). Midstream voided urine samples were analyzed using standard urine culture and long-read, near full-length 16S rRNA gene sequencing with the Nanopore 16S Barcoding kit and MinION system. RESULTS: Fifteen OAB patients and twelve controls were included, with similar ages (9.19±2.19 vs 8.35±2.92 years; p=0.386). Microbiome analysis was completed in 15 cases and 8 controls after exclusion of PCR negative samples. The most frequently detected bacteria were Campylobacter ureolyticus (32%), Ezakiella massiliensis (22%) and Peptoniphilus harei (20%). Alpha and beta diversity were both low, with no statistically significant differences between groups. Microbiome composition analysis showed a higher relative abundance of Gram-positive genera, including Streptococcus, Staphylococcus and Anaerococcus, in OAB patients compared with controls. CONCLUSION: This exploratory pilot study suggests qualitative urogenital microbiome differences in children with OAB, particularly a higher relative abundance of Gram-positive genera, despite no significant differences in diversity; larger studies are needed to confirm the clinical relevance of these hypothesis-generating findings.