Lactase deficiency lactose

Lactose Milk. May occur in urine during pregnancy. In lactase deficiency, malabsorption leads to diarrhea and flatulence. 

Symptoms of lactase deficiency after ingestion of lactose (milk products) include... 

Galactose intolerance Voriconazole tablets contain lactose and should not be given to patients with rare hereditary problems of galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption. 

The real need for lactose-free milk products is hmited as most lactase-deficient adults can tolerate larger amounts than they are likely to consume. 

There are several forms of intolerance to lactose and galactose. Primary adult lactase deficiency is a normal age-related decrease in lactase activity seen in the majority of adults. Secondary lactase deficiency is a transient state of low enzyme activity following injury to the intestinal mucosa as a result of diseases such as celiac sprue, infectious gastroenteritis, and protein-calorie malnutrition. The last two states are common conditions (Dahlqvist 1983). 

Savaiano, D. A., AbouElAnour, A., Smith, D. E., and Levitt, M. D. (1984). Lactose malabsorption from yogurt, pasteurized yogurt, sweet acidophilus milk, and cultured milk in lactase-deficient individuals. Am. J. Clin. Nutr. 40(6), 1219-1223. 

Osmotic diarrhoea occurs when a non-absorbable substance draws fluid into the intestine by osmosis, for example lactase deficiency, when unabsorbed lactose remains in the intestine. This type of problem also occurs in malabsorption disorders, for example in celiac disease. 

Thousands of diseases related to deficient or defective enzymes occur, many of which are rare. For example, in phenylketonuria (which has an incidence of 1 in 10,000 births in whites and Asians), the enzyme phenylalanine hydroxylase, which converts phenylalanine to tyrosine, is deficient. Phenylalanine accumulates, and tyrosine becomes an essential amino acid that is required in the diet. Mental retardation is a result of metabolic derangement. A more common problem is lactase deficiency, which occurs in 69% to 90% of American Indians, blacks, and Asians, and in 10% of whites. Lactose is not digested normally and accumulates in the gut where it is metabolized by bacteria. Bloating, abdominal cramps, and watery diarrhea result. 

Intestinal lactase deficiency is a common condition in which lactose cannot be digested and is oxidized by bacteria in the gut, producing gas, bloating, and watery diarrhea. 

D. Galactose and glucose would be lower in a person with a lactase deficiency, because lactose in the milk would not be cleaved to produce galactose and glucose. 

Lactose is sometimes detected in the urine of women during lactation and occasionally toward the end of pregnancy. Patients with lactase deficiency, a common disorder caused by a congenital or acquired deficiency of intestinal lactase, exhibit abdominal pain, diarrhea, and lactose in the urine. 

Lactose Intolerance (Milk Intolerance) Lactose intolerance is the most common disorder of carbohydrate absorption. Lactase deficiency occurs in the majority of human adults throughout the world and appears to be genetically determined. The prevalence is high in persons of African and Asian ancestry ( 65%) and low in persons of Northern European ancestry. Lactase deficiency in which mucosal lactase levels are low or absent at birth... 

The answer is b. (Murray, pp 190—198. Scriver, pp 1521-1552. Sack, pp 121-138. Wilson, pp 287-317.) In many populations, a majority of adults are deficient in lactase and hence intolerant to the lactose in milk. In all populations, at least some adults have lactase deficiency (223000). Since virtually all children are able to digest lactose, this deficiency obviously develops in adulthood. In lactase-deficient adults, lactose accumulates in the small intestine because no transports exist for the disaccharide. An outflow of water into the gut owing to the osmotic effect of the milk sugar causes the clinical symptoms. Steatorrhea, or fatty stools, is caused by unabsorbed fat, which can occur following a fatty meal in persons with a deficiency of... 

In adults suspected of having a lactase deficiency, the diagnosis is usually made inferentially when avoidance of all dairy products results in relief of symptoms and a rechallenge with these foods reproduces the characteristic syndrome. If the results of these measures are equivocal, however, the malabsorption of lactose can be more specifically determined by measuring the H2 content of the patient s breath after a test dose of lactose has been consumed. 

Many adnlts who have a lactase deficiency develop the ability to ingest small amonnts of lactose in dairy products without experiencing symptoms. This adaptation probably involves an increase in the population of colonic bacteria that can cleave lactose and not a recovery or induction of hnman lactase synthesis. For many individuals, dairy products are the major dietary source of calcium, and their complete elimination from the diet can lead to osteoporosis. 

Lactase is iocated in the brush border (microviiii) of small intestinal enterocytes. Lactase deficiency can be primary, secondary or rarely, congenital. Dietary lactose accumulates causing flatulence and diarrhoea. 

Treatment is achieved by avoiding galactose and lactose in the diet. (NB Do not confuse these conditions with lactose intolerance associated with lactase deficiency Fig. 20.1.)... 

Sucrase (also called saccharase and invertase) hydrolyzes sucrose. In contrast to the abundant information available on the yeast invertase, little is known of the mammalian sucrases. The significance of invertase and lactase in absorption is illustrated by inborn errors of metabolism in which these two enzymes are absent in the intestinal secretion. (The fact that lactase deficiency does not interfere with growth indicates that the galactose needed for biosynthesis of brain lipids or lens proteins can be synthesized endogenously in amounts sufficient to fulfill the metabolic requirements.) In that case, there is an intolerance to lactose or sucrose with no increase in blood glucose levels or without an increase in the levels of disaccharides... 

Gallagher et al. (1974) studied the effect of fermented dairy products (buttermilk, yogurt, and cottage cheese) on lactose tolerance and calcium absorption in three lactase-deficient subjects. Three diets (fermented dairy products, completely lactose-free diet, and nonfermented dairy products) were served in sequence for 4 d each. The three lactase-deficient patients tolerated the fermented dairy products without symptoms of lactose intolerance, whereas consumption of nonfermented dairy products... 

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. 

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... 

An intestinal disaccharidase which cleaves lactose to yield glucose and galactose. Lactase deficiency can occur which may be congenital or acquired. 

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