Normal Bacteria in the Bladder?

I suspect that if you ask most people (including most health providers) whether it is normal to have bacteria in the bladder, you would hear an emphatic “NO!”. The conventional wisdom has long been that the bladder is a sterile environment. But for many years there has been mounting evidence that this simply is not true. A recent review article written by Thomas-White et al provides an excellent history and summary of our developing understanding of normal and beneficial bacteria found in the bladder. These authors also detail their own research which is helping to lead to a radical new understanding of what constitutes a healthy bladder.

This enlightening paper begins by pointing out that our misunderstanding of urine as sterile dates back to the 19^th century when we were just beginning to grasp the nature of bacteria. This idea of a sterile bladder delayed one of the most important advancements in our treatment of patients with neurologic injuries of the bladder: self-catheterization. Prior to the 1960’s, patients with urinary retention were not told to self-catheterize out of fear that it would lead to infections. Unfortunately, the opposite is true and infections are actually prevented by catheterization in these patients.

Most importantly, the authors detail their ground-breaking new work that is advancing our understanding that not only are healthy bladders full of bacteria but that some of these bacteria may be very beneficial for bladder health. Their research identifying bacteria that are clearly alive and present in the bladder suggests that patients with overactive bladder (OAB) may lack an abundance of certain Lactobacillus species. These are the same types of bacteria thought to be protective of infection in the intestine and vagina. It may be that these types of bacteria are also protective against developing urinary tract infections.

For decades we have been guided by an overly simple understanding of the bladder and urine that today seems just plain wrong. This may even influence our current over-use of antibiotics, particularly as it relates to bladder bacteria.  Perhaps our abundant use of antibiotics may predispose some patients to recurrent urinary tract infections by killing beneficial and protective bacteria in the vagina and bladder. It is wonderful to see such cutting-edge scientific study that may one day revolutionize the way we approach our bladder health.

Colin M. Goudelocke, M.D.