D-mannose is what’s known as a glyconutrient, making it a health-promoting sugar. A key part of a molecule called glycoconjugates, they play an important role in cellular communication. Glycoconjugates help your cells interact with each other by coating their surfaces with a sugar-like coating. Unlike sucrose and fructose, D-mannose doesn’t interfere with the regulation of your blood sugar or metabolism because only very small amounts are metabolized. D-mannose acts more like glucose, a sugar that all your cells are designed to use. While D-mannose is absorbed much more slowly than glucose, it doesn’t serve as an energy reserve for your body’s functions like glucose. It is used to help prevent urinary tract infections because it inhibits bacteria from adhering to the walls of the urinary tract. If bacteria can’t latch onto your bladder, it’s less likely to cause an infection.