Lactose tolerance test

Why is an overnight fast required before the lactose tolerance test or the breath hydrogen test is administered ... 

Hermans MM, Brummer RJ, RuijgersAM, et al. The relationship between lactose tolerance test results and symptoms of lactose intolerance. Am / Gastroenterol 92 98-104,1997. 

The symptoms of lactose intolerance are caused by the osmotic effect of the unabsorbed lactose, which increases water and sodium levels in the lumen. Unabsorbed lactose, upon reaching the colon, can be fermented by colonic flora, which produces gas, causing abdominal distension and discomfort. A lactose tolerance test has been developed based on the measurement of blood glucose level and the hydrogen level in the breath. However, its usefulness has been questioned as the test is based on a 50 g dose of lactose. 

A 24-year-old African-American female presents with complaints of intestinal bloating, gas, cramps, and diarrhea following a meal inclnd-ing dairy products. A lactose-tolerance test confirms your suspicion that she had a deficiency of lactase in her intestine. Which of the following dairy prodncts conld yon recommend that wonld be least likely to canse her difficnlties in the fnture ... 

Gastroesophageal reflux scan Gastrointestinal bleeding scan Helicobactor pylori antibodies 5-Hydroxyindoleacetic acid Lactose tolerance test Laparoscopy... 

A test used in the investigation of intestinal lactase deficiency. It consists of the oral administration of lactose followed by the collection of blood samples in which glucose is measured. If intestinal lactase is present, the lactose is broken down to glucose and galactose which are then absorbed. The blood glucose level should therefore increase. However, this does not occur if there is a deficiency of lactase. A flat lactose tolerance test should, however, be followed by a glucose tolerance test in order to check that a generalized malabsorption does not exist. 

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). 

By a disaccharide tolerance test. For instance if lactase deficiency is suspected, lactose is given orally. This should normally be broken down to glucose and galactose and the... 

Direct connections between observed toxicity and formulation components is uncommon and it is usually assumed that vehicles and other nontest chemical components are innocuous or have only transitory pharmacological effects. Historically, however, this has certainly not been the case. Even lactose may have marked toxicity in individual test animals (or humans) who are genetically incapable of tolerating it. 

Kwon, P. H., Jr., Rorick, M. H. and Scrimshaw, N. S. 1980. Comparative tolerance of adolescents of differing ethnic background to lactose-containing and lactose-free dairy drinks. II. Improvement of a double-blind test. Am. J. Clin. Nutr. 33, 22-26. 

A report from Sweden (Rasic and Kurmann, 1978) indicated that nine out of 11 lactose-intolerant individuals tolerated yogurt. Nichols (1978) administered acidophilus milk (5 ml/kg/d) to six lactase-deficient subjects. On the basis of hydrogen breath test results, it was concluded that Lactobacillus acidophilus did not promote additional lactose hydrolysis. However, the dose of microorganisms (2-4 x 10 /ml) used in this study is much lower than typical counts in fermented milk products. From the same laboratory (Gilliland and Kim, 1981), it was later reported that administration of acidophilus milk containing more natural numbers resulted in decreased breath hydrogen production by lactose-intolerant individuals. 

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