Cranberry capsule ingestion and bacterial anti‐adhesion activity of urine

Abstract

Clinical, epidemiological and mechanistic studies support the role of cranberry in maintaining urinary tract health. Current studies suggest cranberry proanthocyanidins (PACs) may prevent urinary tract infections by interfering with adhesion of certain pathogenic E. coli to uroepithelial cells. The current study measured bacterial anti-adhesion activity in human urine after consumption of TheraCran™ cranberry capsules. One 650-mg capsule (equivalent to 16.5 mg oligomeric PACs/capsule) was administered BID to six healthy middle-aged participants over a 2-day period, followed by urine collection over an 8- hr period. An average of 3 hrs following capsule consumption, 67% of urines exhibited bacterial anti-adhesion activity. Activity persisted for at least 8 hrs, suggesting potential protection against bacterial attachment in the uroepithelium over this period. Urinary pH averaged 6.5, eliminating a bacteriostatic effect. No anti-adhesion activity was detected in urines prior to capsule consumption. The threshold for in vitro anti-adhesion activity of the capsules was determined to be 3.5 mg/ml utilizing a mannose-resistant human red blood cell hemagglutination assay specific for P-fimbriated E. coli bacteria. Results suggest that consumption of cranberry capsules may be an effective means of preventing bacterial adhesion in human urine, which could potentially reduce the incidence of urinary tract infections. This work was supported by Theralogix, LLC.