Kate Johnson

October 21, 2013

LAS VEGAS — Bacterial communities isolated from the urine of women with urinary incontinence differ depending on the type of incontinence, according to a study that, for the first time, suggests that bladder microbiota could play a role in this condition.

"This opens our eyes to the possibility that bacteria, by themselves or in their community, may interact with muscles, urothelial cells, or other aspects, and make a difference in symptoms," Linda Brubaker, MD, from the Loyola University Stritch School of Medicine in Chicago, told Medscape Medical News.

Dr. Brubaker presented the study findings here at the American Urogynecologic Society 34th Annual Scientific Meeting.

The investigators analyzed 16 catheterized urine samples taken from women with 4 different subtypes of urinary incontinence.

Samples were evenly divided into stress urinary incontinence, urgency urinary incontinence, mostly stress urinary incontinence, and mostly urgency urinary incontinence, according to symptoms reported on the Pelvic Floor Distress Inventory.

All patients were free of urinary tract infection, both clinically and as determined with a urine culture.

Each sample was split, with one portion sent for conventional urine culture and Gram stain analysis, and the remaining portion sent for DNA sequencing analysis.

It's a very alluring analogy to think that urgency incontinence might be caused by a single bacteria or group of bacteria, but I don't think we're ready to go there yet.

The sequencing analysis showed that the microbiota of patients with the 2 types of urgency urinary incontinence and could be easily distinguished from those of patients with the 2 types of stress urinary incontinence, and that the bacterial mix in the latter group was much less diverse, said Dr. Brubaker. "This was our first inkling that the paradigm might be shifting and that we might have some new insights into urgency incontinence and perhaps even stress incontinence."

"This is the first study to provide evidence supportive of an infectious association or link to a subtype of urge urinary incontinence analagous to that seen with peptic ulcer disease," session moderator Michael Heit, MD, from Indianapolis, told Medscape Medical News.

"Hopefully, in the near future, therapies can be directed at bacteria or their antigens identified in the urinary bladder of affected women, reducing symptoms and the impact on daily activities attributable to urge urinary incontinence," he added.

Previous work by Dr. Brubaker and her team has shown that even healthy women with no bladder symptoms have bacteria in their bladder (J Clin Microbiol. 2012;50:1376-1383).

"A big take-home message is that bacteria aren't always bad; it certainly isn't always a sign of infection," noted Dr. Brubaker. "The paradigm that we still teach is that the bladder is a sterile environment and if there are bacteria present, they are pathogens and should be killed. That probably needs some serious reconsideration."

She said the identification of specific bacteria associated with urinary incontinence makes it tempting to think they are the cause, but this is premature.

"It's a very alluring analogy to think that urgency incontinence might be caused by a single bacteria or group of bacteria, but I don't think we're ready to go there yet," said Dr. Brubaker. "This does give us an opportunity to think about whether we can alter the microbiome in some way, and maybe make patients who don't seem to respond to treatment more likely to respond. It would be very nice to learn how to modulate bacterial communities without relying on antibiotics."

Dr. Brubaker and Dr. Heit have disclosed no relevant financial relationships. Coauthor Elizabeth R. Mueller, MD, from the Stritch School of Medicine, reports being a speaker and doing contracted research for Allergan, and doing consulting and contracted research for Astellas. Coauthor Alan J. Wolfe, PhD, also from the Stritch School of Medicine, reports receiving research funding from Astellas Scientific and Medical Affairs.

American Urogynecologic Society (AUGS) 34th Annual Scientific Meeting: Paper 1. Presented October 17, 2013.


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