The American cranberries (Vaccinium macrocarpon) have been consumed for centuries to prevent urinary tract infections (UTI), 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 UTI 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 small intestine. They are degraded by microbes in colon.The pre-preliminary study showed that the urine from a portion of study participants had anti-adhesion activity, suggesting there are polymorphisms in human's ability to metabolize cranberry bioactives. Based on these observations, the investigators formulate a novel hypothesis that not all, but a fraction of women harbor specific gut microbes with the ability to catabolize cranberry bioactives to anti-adhesion metabolites in the urine; therefore, the variation of gut microbiome is the underlying mechanism for metabolic polymorphisms and disparity in UTI prevention. The investigators propose that UTI susceptible women can be divided into responders and non-responders depending on whether cranberry intake increase anti-adhesion activity of their urine. The overall objectives are to identify gut microbes and anti-adhesive urinary biomarkers which significantly contribute to the anti-adhesion of E. coli. The expected result will be to generate strong preliminary data showing the differences of gut microbiome between responders and non-responders in additional to correlations between gut microbes and candidate anti-adhesion biomarkers in the urine of UTI susceptible women.
The investigators pre-preliminary study showed that the urine from a portion of study participants had anti-adhesion activity. The investigators propose that UTI susceptible women can be divided into responders and non-responders depending on whether cranberry intake increase anti-adhesion activity of their urine. The overall objectives are to identify gut microbes and anti-adhesive urinary biomarkers which significantly contribute to the anti-adhesion of E. coli.