disaccharidase test

Last reviewed 01/2018

Deficiency of small bowel disaccharidase activity can be tested in the following manner:

  • 50 g of the appropriate disaccharide e.g. lactose is given orally in 500 ml of water
  • the blood glucose response is determined by serial measurements
  • the control test is performed on the next day when 25 g of each of the constituent monosaccharides is given orally and the blood glucose response is monitored

Significant reduction in the area under the blood glucose response curve when the disaccharide is given indicates disaccharidase deficiency.

Hydrogen breath tests may be used to detect the bacterial metabolism of malabsorbed disaccharides.