Modern microbiological research using advanced sequencing and culturing techniques has thoroughly refuted the traditional dogma that the healthy human bladder is entirely sterile, establishing the presence of a resident urinary microbiome (urobiome).
The claim that human urine is entirely sterile inside the bladder represents an older medical dogma that has been overturned by modern molecular and culturomics research. Multiple retrieved papers (such as [1], [2], [3], [6], [8], and [11]) explicitly discuss the healthy urinary microbiome or urobiome, confirming that bacteria natively inhabit the bladder even in healthy individuals. Therefore, the claim is clearly refuted by the scientific evidence.