Over 90% of all urinary tract infections are caused by Escherichia coli (E. coli) which is found as part of the "normal microflora" in every intestinal tract. In most cases bacteria enter the urinary tract through the urethral opening. Many bacteria are simply washed away by the down-flow of urine. E. coli, however, are covered with tiny 'finger-like' projections. At the top of these projections are amino acid/sugar complexes called "lectins" which allow the bacteria to stick to the inside walls of the urinary tract and even work their way upward. D-Mannose, a naturally occurring simple sugar, sticks to the E. coli lectins even better than the lectins stick to human cells. When a large quantity of this sugar is present in the urine, it literally coats any E. coli present. They can no longer stick to urinary tract walls and are washed away with normal urination. Only very small amounts of D-mannose are metabolized by the body. Most is excreted through the kidneys into the urine and bladder, so it doesn't interfere with blood/sugar regulation, even in diabetics. Also, since it is absorbed in the upper gastro-intestinal tract, it does not relocate "friendly" E. coli or other beneficial bacteria normally present in the colon.