Cranberry compounds that prevent UTI identified

Scientists have identified active compounds in cranberries that help prevent urinary tract infection (UTI) in humans, a finding that may pave the way for treating the painful condition.

Many people have heard that drinking cranberry juice can help prevent UTIs. Although clinical trials of this popular folk remedy have produced mixed results, some studies have shown that drinking cranberry juice can keep bacteria that cause UTIs from sticking to cells lining the urinary tract.

Researchers from University of Mississippi and University of Georgia in the US identified cranberry oligosaccharides in the urine of cranberry-fed pigs that could be responsible for this activity.

Doctors usually prescribe antibiotics to treat UTI, but this could contribute to the rise of antibiotic-resistant bacteria.

To enable better UTI prevention strategies, researchers wanted to identify active compounds from cranberries that end up in urine and potentially keep bacteria from adhering to human cells.

They fed female pigs dried cranberry powder, collected their urine and used chromatography to separate it into fractions of differently sized molecules.

Then, they screened the samples for anti-adhesion activity against the E coli bacteria that cause UTIs.

Researchers found that proanthocyanidins, the compounds previously proposed to be responsible for cranberry's apparent UTI prevention properties, were absent from the active urine fractions.

Instead, the researchers detected oligosaccharides called arabinoxyloglucans in those samples.

These complex carbohydrates, related to cellulose, are difficult to detect and isolate, which could explain why they hadn't previously been identified as anti-adhesive components of cranberry, the researchers said.