In a randomized, double-blind, placebo-controlled clinical cross-over study with 18 subjects of both sexes (aged 21-52 years), the effect of cranberry (Vaccinium macrocarpon) and pumpkin seed extract combination (Cystorenal Cranberry plus) on the urinary tract through inhibition of Escherichia coli adherence to urothelial cells was examined. With the ingestion of Cystorenal Cranberry plus, the bacterial adherence was decreased by 33.4% compared to the placebo. The recommended amount of the preparation is sufficient to protect the healthy bladder. There was no adverse effects observed.