Tuesday, 16 July 2013

How Do Cranberries Fight Urinary Tract Infections?

Cranberries by Melodi2 at morguefile.com
Cranberries have been associated with relief from urinary tract infections, or UTIs, for a very long time. They are healthy and nutritious fruits and are a great addition to anyone's diet. Their apparent ability to help urinary tract infections has been especially interesting to many people, though, particularly women suffering from the pain and discomfort of a UTI.

Recent research has suggested that cranberry chemicals called proanthocyanidins prevent bacteria from sticking to the wall of the urinary tract. Now scientists at McGill University in Canada have found further evidence supporting this idea.

The Effects of Cranberries on Bacteria

The researchers have discovered that cranberry powder inhibits a bacterium called Proteus mirabilis from swarming and swimming through agar in a laboratory dish. This bacterium is frequently associated with complicated UTIs. Agar is a growth medium that contains nutrients for bacteria.

The McGill researchers have also discovered that when they increased the concentration of cranberry powder the amount of urease produced by Proteus mirabilis decreased. Urease is an enzyme that is part of the bacterium's infective arsenal.

What are Swarming Bacteria?
Patterns in agar created by swarming bacteria
Photo by Julio514 at Wikimedia Commons,
CC BY SA-3.0 License

Swarming is an interesting process in which bacteria coordinate their movements and move rapidly en masse over a surface, almost as though they are a multicellular organism. Swarming bacteria have a different shape from individual, swimming bacteria. They're elongated and have many flagella. Flagella are moving, whip-like structures extending from the bacterial cell and are used in propulsion. Lab observations have shown that as swarming bacteria move away from their initial position, they form interesting patterns in agar that often look like the branches of a tree.

Other Benefits of Cranberries in UTIs

In earlier research the scientists found that cranberry proanthocyanidins inhibited the action of a type of E. coli that causes urinary tract infections. The chemicals inhibited a gene that controls the production of flagella.

Researchers have also found that material made of silicon and cranberry inhibits the spread of Proteus mirabilis. This discovery could be significant in the creation of urinary catheters, which can sometimes cause infections when they're placed in the urinary tract.

The results of the cranberry research are both interesting and exciting. They show that cranberry fights bacteria in the lab. This doesn't necessarily mean that it will do the same thing in the human body. However, combined with the anecdotal reports that cranberry can help UTI's, the research results are very encouraging.

UTIs and Antibiotic Resistance

According to Professor Nathalie Tufenkji at McGill University, more than 150 million UTIs occur around the world every year. Antibiotics are the standard treatment for a urinary tract infection, but bacterial resistance to antibiotics is becoming a serious problem. It would be wonderful if natural treatments such as the use of cranberries could help or even replace the use of antibiotics.