Xylose tolerance test

Santini, R., Jr., Sheehy, T. W., and Martinez-De Jesus, J., The xylose tolerance test with a five-gram dose. Gastroenterology 40, 772-774 (1961). 

The carbohydrate analyzer has shown that there are considerable differences in excretion patterns of carbohydrates in disease. Many carbohydrates are excreted in excess in renal glycosuria and diabetes mellitus (Yl). Other abnormalities, such as pancreatic insufiSciency and lactose deficiency, show several carbohydrate excretion abnormalities. The presence of large amounts of xylulose and other sugars during ingestion of xylose indicates that the xylose tolerance test may not be a true measurement of absorption since that sugar apparently also metabolizes (Yl). 

P-Xylose occurs in grains and fruits. It is a pentose with a structure similar to its hexose cousin glucose. Since it is absorbed and excreted mainly unchanged, the xylose tolerance test is used to diagnose intestinal malabsorption syndromes. 

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