The long-standing concept of sterile urine has been progressively revised with the recognition of a resident urinary microbiome (urobiome) in both healthy subjects and individuals with lower urinary tract symptoms. Patients with neurogenic lower urinary tract dysfunction (NLUTD) represent a particularly vulnerable group, characterized by frequent microbiome alterations, asymptomatic
bacteriuria, and urinary tract infections (UTIs). However, evidence derived from enhanced quantitative urine culture (EQUC) remains limited. This study aimed to characterize urinary microbiome profiles in NLUTD patients using EQUC, compare microbiological patterns across clinical phenotypes and non-neurogenic controls, and explore the relationship between microbial features, catheterization, and UTI status through multivariate analytical approaches.

This prospective observational study included urine samples from patients with NLUTD and a control group with non-neurogenic LUTS. All samples were processed using EQUC. Patients were stratified according to clinical phenotype (overactive bladder [OAB] vs chronic urinary retention [CUR]), use of clean intermittent catheterization (CIC), and UTI status (negative standard culture, asymptomatic bacteriuria, symptomatic UTI). Statistical analyses comprised univariate comparisons and multivariate modeling based on predefined microbiological indices (polymicrobial profile, Gram-positive predominance, uropathogen dominance, commensal-enriched profile), together with penalized logistic regression (LASSO).

A total of 130 patients were analyzed (NLUTD n=100; controls n=30). EQUC identified at least one microbial species in 92.3% of NLUTD patients and 86.7% of controls, with more than 120 distinct taxa detected overall. Escherichia coli was more frequently observed in NLUTD patients compared to controls (32.0% vs 16.7%). Within the NLUTD cohort, polymicrobial profiles (≥2 species) were more prevalent in patients with CUR than in those with OAB (61.5% vs 38.9%), and reached the highest frequency among individuals performing CIC (76.9% vs 54.2% in non-catheterized CUR patients). Stratification according to UTI status demonstrated a progressive shift in microbial composition from standard culture-negative cases to asymptomatic bacteriuria and
symptomatic UTI, the latter being characterized by a predominance of classical uropathogens.

Urinary microbiome alterations in NLUTD appear to be driven primarily by changes in overall microbial composition rather than by the presence of individual species. The use of microbiological indices enabled a more clinically meaningful interpretation of EQUC findings. Moreover, LASSO regression identified a limited number of microbial features independently associated with clinical
outcomes, supporting the concept of a continuum ranging from colonization to overt infection.

In patients with neurogenic bladder, urinary microbiome changes reflect ecosystem-level dysregulation rather than isolated pathogen-driven events. The combined use of EQUC, structured microbiological indices, and penalized regression analysis supports an ecological model of urinary tract dysbiosis, with potential relevance for patient stratification and personalized therapeutic strategies.

Continence 19S (2026) 102551
DOI: 10.1016/j.cont.2026.102551