Use of Hydrogen Breath Testing for Diagnosis of Dietary Fructose Malabsorption

Fructose is a simple monosaccharide which is found in many plant foods. It is also used as a sweetening additive in the form of fructose corn syrup, a mixture of glucose and fructose. Its consumption is, in general, rising among the population. Setting aside the condition of hereditary fructose intolerance (which is relatively rare), it is possible for dietary intake of fructose to overload the enterocytes. This is consistent with the limited absorption capacity of the enterocyte transporter GLUT5, which is used by fructose to cross the intestinal epithelium [1]. Non-absorbed ffructose produces gastrointestinal symptoms from its metabolism by colonic bacteria, which may be an undiagnosed cause of recurrent abdominal pain. It has also been suggested that fructose malabsorption may underlie the gastrointestinal symptoms seen in patients with irritable bowel syndrome [2].