Abstract
The assumption of healthy urine being sterile has been contradicted recently when the existence of urinary microbiota (UM) was revealed. Extended quantitative urine culture is based on longer incubation times in a wide selection of diverse growth conditions; bacteria are detected even in samples reported as negative by the standard urine culture protocol.
Next-generation sequencing helps with taxonomic assignment of prokaryotic DNA fragments according to the sequence in hypervariable regions of the 16S rRNA gene. Human UM is composed of the phyla Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria.
Female UM is dominated by the genus Lactobacillus, male urotypes have not been assigned with certainty to date. Changes in UM have been associated with functional disorders of the genitourinary tract (lower urinary tract symptoms, urge urinary incontinence, neurogenic bladder dysfunction, chronic kidney disease), chronic pelvic pain syndrome, interstitial cystitis and even with urinary bladder cancer.
UM may potentially play many a role; what they are is a matter of ongoing research. UM might be a useful tool in the diagnostics and therapy of disease.