D-mannose is a kind of sugar that is related to glucose.

D-mannose is used for preventing urinary tract infections (UTIs) and treating carbohydrate-deficient glycoprotein syndrome, an inherited metabolic disorder.
 
D-mannose is a glyconutrient, a class of molecules that maintain communication between cells. Although d-mannose is a sugar, unlike glucose, it is poorly absorbed into the bloodstream.
 
Urinary tract health
 
One of the advantages of d-mannose, which is poorly absorbed into the bloodstream, is that it does everything it needs quickly and remains locally in the kidneys, bladder, and urinary tract. Then the sugar leaves your body without being broken down.
 
D-Mannose protects the urinary tract mucosa and prevents particles from sticking to it.
It also has a slight diuretic effect, helping the body "flush out" infections.
Our body also produces mannose.
The researchers believe that taking d-mannose supplements, which increase blood mannose levels, in turn, increase urine mannose levels. It is primarily useful for preventing urinary tract infections.
 
Antibacterial properties
 
Because of the way it targets the urinary system, d-mannose is predominantly used to treat painful urinary tract infections. Such infections are extremely common: every fifth woman encounters them at least a couple of times in her life. Symptoms include irritation and burning sensation when urinating, lower abdominal pain, and cloudy urine that may also contain blood.
 
As it passes through the urinary system, d-mannose coats the walls of the bladder and urinary tract with sugars, which prevent bacteria from taking hold.
In addition, it stimulates the growth of the Tamm-Horsfall protein (THP ( 3 )), the most abundant protein in urine, which naturally binds to bacteria.
 
Most urinary tract infections are caused by E. coli, which is particularly effective against d-mannose, clearing a significant number of associated infections in just one day.
For this reason, d-mannose is recommended as an alternative to antibiotics in the treatment of urinary tract infections. 
 
Gastrointestinal health
 
D-Mannose can act as a prebiotic, which means it supports and stimulates the growth of healthy gut bacteria.
Gut microflora health is associated with improved weight control, cardiovascular health, blood sugar regulation, and beneficial effects on a number of different diseases.
Also d-mannose helps to bind and block lectins in the digestive tract. Lectins are a type of protein found in beans, grains, seeds, and some vegetables and fruits. It is difficult for the body to digest them since they are not broken down by the action of gastric juice. Consuming these foods raw can lead to irritation. D-Mannose binds to lectins, helping the body eliminate them through urination.
 
Type 1b carbohydrate deficiency glycoprotein syndrome
 
Type 1b carbohydrate-deficient glycoprotein syndrome is an inherited genetic disorder that interferes with the absorption of protein in the intestines. D-Mannose helps stop this protein loss and promotes healthy liver function. It also prevents blood diseases and regulates blood sugar levels in patients with this syndrome.
 
*These statements have not been evaluated by the Food and Drug Administration. The product above is not intended to diagnose, treat, cure, or prevent disease.