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At least 487 records · Page 27Linked to original sources
PubMed1977

Application of a simple gas chromatographic technique for measuring breath hydrogen.

A simple gas chromatographic technique for analyzing H2 in expired air with a compact, relatively inexpensive gas chromatography specifically adapted for H2 analysis is described. Modifications in the basic chromatograph included increasing the capacity of the sample loop, lengthening the column, and using argon as the carrier gas to increase the sensitivity of the system. Methods for collecting and storing respiratory gas samples and for quantifying the results are described for clinical studies of carbohydrate malabsorption. Small errors in collection and quantitation are introduced by the method, but they are minor in relation to the changes in H2 concentration which are seen with significant malabsorption. This simplification of chromatograph technology could increase the general availability of this convenient, noninvasive and well-tolerated test of intestinal absorption of carbohydrates such as lactose.

Adult↗
PubMed1992

Use of oral tolerance tests to investigate disaccharide digestion in neonatal foals.

Oral tolerance tests were performed on 13 neonatal foals to determine their ability to digest disaccharides on d 1, 3 and 5 postpartum. Foals were assigned randomly to treatments consisting of 20% (wt/vol) solutions of either maltose, lactose, or sucrose, dosed at 1 g/kg of BW, or glucose, dosed at .5 g/kg of BW. After a 2-h fast, an initial blood sample was collected via jugular catheter. Foals were administered the appropriate solution orally, and blood was collected every 15 min for 1 h and then every 30 min for 3 h. Plasma glucose increased after dosing with lactose or glucose but not with sucrose. Plasma glucose concentrations increased slightly on d 3 and 5 in foals dosed with maltose. These findings suggest that although lactose is well digested by neonatal foals, maltose is digested only slightly, and sucrose is not digested by d 5. Results of this experiment indicate that maltose and sucrose would not be suitable for inclusion in artificial diets for foals less than 1 wk old. Oral tolerance tests could be useful for determining the ability of premature or sick foals with lactose intolerance to digest alternate carbohydrate sources.

Animal Feed↗
PubMed1970

Plasma insulin response to oral carbohydrate in patients with glucose and lactose malabsorption.

Plasma insulin levels were determined following oral glucose in 12 patients with adult coeliac disease, after oral lactose in four patients with alactasia, and in age-matched control subjects. In coeliac patients the insulin response was greater than expected from the small rise in blood sugar, and no correlation was found between plasma insulin and sugar levels at any period during the test. The separation of the plasma insulin curve from the blood sugar curve after glucose is in keeping with the concept that a factor responsible for stimulating insulin secretion is released from the gut during or after absorption of glucose. In patients with selective lactose malabsorption (alactasia) administration of lactose by mouth failed to elicit any insulin response, indicating that the insulin-releasing effect of the bowel is not activated merely by the presence of intraluminal carbohydrate.

Administration, Oral↗
PubMedDate not supplied

Lactose digestion and clinical tolerance to milk, lactose-prehydrolyzed milk and enzyme-added milk: a study in undernourished continuously enteral-fed patients.

We investigated: (1) the capacity to digest and tolerate the lactose administered by continuous infusion of intact milk to undernourished tube-fed patients, and (2) the effectiveness of lactose-prehydrolyzed milk, and of the addition of exogenous lactase to milk at infusion time, to reduce lactose maldigestion and increase clinical tolerance. Carbohydrate digestion was evaluated in 10 subjects with the hydrogen breath analysis test during 8 hr of observation. Lactose intolerance was determined by evaluation of subject's symptoms. With the infusion of intact milk (IM), none of the subjects were able to efficiently digest the lactose infused (5.6 +/- 0.35 g/hr, mean +/- SEM) and 86% of them experienced major symptoms of intolerance. With the infusion of lactose-prehydrolyzed milk (HM) and enzyme-added milk (EM) there was a highly significant reduction in lactose maldigestion. More importantly, major symptoms were present in only 10% of subjects with EM, and were completely eliminated with HM. Lactose maldigestion and intolerance represent a major limitation for the application of milk-based polymeric formula for liquid diets in undernourished subjects. The use of exogenous beta-galactosidases represents an alternative to avoid such reactions.

Adult↗
PubMed1994

Milk tolerance in adults with ulcerative colitis.

OBJECTIVES: There has been concern in the literature and among physicians and patients that milk intolerance may contribute to disease activity in ulcerative colitis. We sought to define whether patients with ulcerative colitis have problems with milk tolerance. METHODS: 1) A questionnaire was administered to a group of gastroenterologists. 2) Consecutive unselected ulcerative colitis patients were administered a questionnaire regarding issues concerning their ingestion and tolerance of milk products. 3) Patients, and age- and ethnically matched controls, underwent lactose hydrogen breath testing at a 50-g dose, and if intolerant, returned for testing at a 12.5-g dose. RESULTS: Eighty percent of responding physicians stated that they recommend avoidance of milk products at some time to their patients. Thirteen of 29 (44%) ulcerative colitis patients were lactose intolerant compared with five of 14 (36%) controls (p = 0.57). Of 11 subjects returning for the 12.5-g test dose, only three (28%) were intolerant. Of 10 ulcerative colitis patients tested during a flare, only two (20%) were intolerant. Nineteen of 28 (66%) patients reduced or eliminated milk products from their diet, but only 10 (45%) of these patients were lactose intolerant. The discordance rate for predicting lactose tolerance status among patients was 35%. By logistic regression analysis, age (p = 0.04) and ethnicity (p = 0.006) were the only variables that were predictive of an abnormal lactose hydrogen breath test. CONCLUSIONS: There are common misperceptions among physicians and patients about lactose intolerance in ulcerative colitis. Lactose intolerance in patients with ulcerative colitis is dependent on their age and ethnicity and not any particular aspects of their disease. The proscription of milk products during flares of disease by many physicians is not supported by this study.

Adult↗
PubMed1997

Improvement of lactose digestion by humans following ingestion of unfermented acidophilus milk: influence of bile sensitivity, lactose transport, and acid tolerance of Lactobacillus acidophilus.

The influence of bile sensitivity, lactose transport, and acid tolerance of Lactobacillus acidophilus on in vivo digestion of lactose was investigated. Four strains of L. acidophilus exhibiting varied degrees of lactose transport, beta-galactosidase activity, and bile sensitivity were used to prepare unfermented acidophilus milks. Lactose malabsorption was evaluated by measuring breath H2 excretion off 11 lactose maldigesting subjects following ingestion of four acidophilus test milks. Test meals were fed in a randomized double-blind protocol. Consumption of acidophilus milk (2% fat) containing strains B, N1, and E significantly reduced mean total H2 production compared with that of the control reduced-fat (2% fat) milk, but milk containing strain ATCC 4356 did not differ from the control. Acidophilus milk containing L. acidophilus N1 was the most effective of the four acidophilus milks in improving lactose digestion and tolerance. Strain N1 exhibited the lowest beta-galactosidase activity and lactose transport but the greatest bile and acid tolerance of the four strains. The results indicated that bile and acid tolerance may be important factors to consider when L. acidophilus strains are selected for improving lactose digestion and tolerance.

Adult↗