American Cranberries to Prevent UTIs in Susceptible Women

The American cranberries (Vaccinium macrocarpon) have been consumed for centuries to prevent urinary tract infections (UTIs), which affect 50% of women in their lifetime. However, NIH-funded clinical trials of cranberries on UTI in the last 20 years yielded conflicting results, but the reasons are unknown. About 90% of UTIs are initiated by adhesion of uropathogenic E. coli on urinary tract epithelia. It was reported that human urine after cranberry intake inhibited the adhesion of E. coli. A-type procyanidins and xyloglucans are the presumed bioactives in cranberries; however, none of these compounds are absorbable in the small intestine. They are degraded by microbes in the colon. The pre-preliminary study showed that the urine from a portion of study participants had anti-adhesion activity, suggesting there are polymorphisms in humans' ability to metabolize cranberry bioactives. The investigators propose that UTI susceptible women can be divided into responders and non-responders depending on whether cranberry intake increases anti-adhesion activity of their urine.

Inclusion criteria

• Healthy women participants
• BMI 18.5-29.9 kg/m2
• At least 110 pounds in weight

Exclusion criteria

• BMI≥ 30 kg/m2
• Pregnancy and breast-feeding
• Smoking, frequent alcohol use
• History of any clinically important disorder that may interfere with interpretation of the results,
• Intake of medication that might influence the outcome of the study