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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies have shown reduced breath hydrogen (H2) excretion in methane (CH4)-producing healthy individuals following ingestion of lactulose. This questions the reliability of the breath hydrogen test (BHT) in CH4 excretors, but the relationship between CH4 and H2 excretion in other clinical applications of the BHT is not known. We reviewed BHT results in two groups of subjects: (1) 385 children tested for lactose malabsorption in a hospital setting, and (2) 109 lactose-malabsorbing patients tested with a home kit. The percentage of lactose malabsorbers in group 1 (51%) was the same regardless of CH4-producing status (P = 0.97). The BHT data from group 2 showed a positive correlation (r = 0.6, P < 0.000001) between the magnitude of the rise in CH4 and H2 concentrations, and the H2 excretion curves were significantly higher in the CH4-producing individuals. We conclude that attention to CH4-producing status is not necessary in the interpretation of the lactose BHT.
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PMID:Relationship between methane production and breath hydrogen excretion in lactose-malabsorbing individuals. 844 74

Rice carbohydrate malabsorption is common in Burmese village children and adults and may contribute to diminished growth. Its diagnosis depends on a rice breath hydrogen test, which has limitations. Almost 20% of Burmese children under age 5 produce methane, compared with less than 7% of children in Africa and Hong Kong. If an increased carbohydrate load in the colon due to rice malabsorption provides increased substrate for methanogenic bacteria in the left colon, higher fasting breath methane concentrations might be a simpler method of diagnosing rice malabsorption. We tested breath hydrogen and methane over a 4-h period and did anthropometric measurements in 142 subjects, 79 children, and 63 adults. Seventy percent of children were rice-malabsorbers. Methane production occurred in 20% of children under 5 years of age and increased to 60% of adults. There is an association of rice malabsorption with reduced length. There was not correlation between rice malabsorption and breath methane, and the concentration of breath methane does not, therefore, indicate rice absorption status and cannot replace rice breath hydrogen tests.
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PMID:Correlation of hydrogen and methane production to rice carbohydrate malabsorption in Burmese (Myanmar) children. 925 24

It has been theorized that colonic production and absorption of short-chain fatty acids (SCFA) is different in methane producers (MP) compared with nonproducers (MNP). Because colonic SCFA may influence systemic lipid metabolism, blood lipids may differ in MP and MNP. To compare serum lipids and SCFA in fasting MP and MNP, we measured breath gases, serum lipids and SCFA in 167 healthy subjects and excluded subjects with abnormal blood lipids. The 66 MP were significantly older than the 63 MNP (49.5 +/- 16.0 vs. 39.6 +/- 17.0 y, P = 0.0009), and breath methane concentrations were weakly correlated with age in MP (r = 0.268, P = 0.03). Mean serum cholesterol was significantly higher in MP compared with MNP, but the differences were not significant after adjusting for age. No significant differences were observed in serum SCFA between the two groups. This study has shown that breath methane increases with age, which may be due to age-related increases in transit time and carbohydrate malabsorption. These results provide no conclusive link between colonic events and serum lipids in MP because, with age, methane production increased as did serum cholesterol. More research is required before any definite conclusions can be drawn.
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PMID:Increased serum cholesterol in healthy human methane producers is confounded by age. 968 55

Fructans (fructooligosaccharides and inulin) are of increasing interest to clinical nutritionists as functional food additives. The chemically closely related food carbohydrates fructose and sorbitol are implicated in functional bowel disease. Intestinal handling of these carbohydrates is incompletely understood. Intestinal absorption, transit, and fermentation (breath hydrogen and methane, venous acetate, blood glucose, and urine fructans) after ingestion of 10-30 g short- and long-chain fructans from chicory were studied by single-blind, crossover randomization in 10 healthy adults. Responses were compared with responses after ingestion of lactulose, fructose, and sorbitol. Breath hydrogen and venous acetate production increased in proportion to increasing fructan dose and were similar to responses to lactulose. The transit times of long-chain fructans were longer than those of short-chain fructans (75 compared with 30 min, P<0.001). Semiquantitative estimates of unabsorbed carbohydrate were not significantly different with either short-chain fructans or lactulose as nonabsorbable standards. Venous acetate curves were less precise estimates of the magnitude of carbohydrate malabsorption than were breath-hydrogen curves (P<0.01). All subjects showed malabsorption of 50 g fructose, resulting in significantly more symptoms than 20 g fructose (P<0.05). Ingestion of sorbitol with equimolar amounts of glucose did not reduce malabsorption or abdominal distress. Abdominal symptoms after fructans increased with increasing dose and decreasing chain length. The overall gastrointestinal effects of short-chain fructans seem similar to those of lactulose. Fructans with different chain lengths may have different physiologic properties and further studies of fructans in disease states are warranted.
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PMID:Fructans of chicory: intestinal transport and fermentation of different chain lengths and relation to fructose and sorbitol malabsorption. 970 Nov 94

Breath tests are a simple and safe alternative to more invasive investigation strategies for many gastroenterological conditions. Both the hydrogen breath tests and the new 13C stable radioisotope breath tests are nonradioactive and safe in children and pregnancy. The range of diseases that can be identified include Helicobacter pylori infection, lactose and fructose intolerance, bacterial overgrowth, bile salt wastage, pancreatic insufficiency, liver dysfunction, and abnormal small bowel transit. In this review, the physiology supporting these tests and the principles of normal gas dynamics in the gut are briefly reviewed and then related to the test preparation and interpretation in two parts: 1) detection of H. pylori and 2) small bowel, pancreatic, and hepatobiliary disorders. A MEDLINE search reviewing all English language abstracts from 1966 to March, 2001 was performed, with an additional review of abstracts from major national meetings from 1997 to 2001. Using the information from this review, the performance characteristics of the various tests were detailed, and an attempt is made to provide some literature-based guidance regarding their indications and limitations. The interpretation of "flat" breath tests and the selective use of methane collection and colonic alkalinization are discussed. Breath tests are valuable tools that are, in general, underutilized in evaluating dyspepsia and functional bloating and diarrhea, as well as suspected malabsorption, including lactose intolerance.
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PMID:Using breath tests wisely in a gastroenterology practice: an evidence-based review of indications and pitfalls in interpretation. 1201 15

The maturational decline in lactase activity renders most of the world's adult human population intolerant of excessive consumption of milk and other dairy products. In conditions of primary or secondary lactase deficiency, the lactose sugars in milk pass through the gastrointestinal tract undigested or are partially digested by enzymes produced by intestinal bacterial flora to yield short chain fatty acids, hydrogen, carbon dioxide, and methane. The undigested lactose molecules and products of bacterial digestion can result in symptoms of lactose intolerance, diarrhea, gas bloat, flatulence, and abdominal pain. Diagnosis of lactose intolerance is often made on clinical grounds and response to an empiric trail of dietary lactose avoidance. Biochemical methods for assessing lactose malabsorption in the form of the lactose breath hydrogen test and direct lactase enzyme activity performed on small intestinal tissue biopsy samples may also be utilized. In some adults, however, high levels of lactase activity persist into adulthood. This hereditary persistence of lactase is common primarily in people of northern European descent and is attributed to inheritance of an autosomal-dominant mutation that prevents the maturational decline in lactase expression. Recent reports have identified genetic polymorphisms that are closely associated with lactase persistence and nonpersistence phenotypes. The identification of genetic variants associated with lactase persistence or nonpersistence allows for molecular detection of the genetic predisposition towards adult-onset hypolactasia by DNA sequencing or restriction fragment length polymorphism analysis. The role for such genetic detection in clinical practice seems limited to ruling out adult-onset hypolactasia as a cause of intolerance symptoms but remains to be fully defined. Attention should be paid to appropriate interpretation of genetic detection in order to avoid potentially harmful reduction in dairy intake or misdiagnosis of secondary lactase deficiency.
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PMID:Genetic variation and lactose intolerance: detection methods and clinical implications. 1528 17

Although malabsorption of small amounts of fructose-sorbitol mixtures occurs frequently in healthy humans, insights into their effects on gastrointestinal motility are poor. The present study addresses the hypothesis that malabsorption of a fructose-sorbitol challenge changes the small intestinal transit rate. Eleven healthy volunteers participated in a double-blind crossover investigation. In random order, the subjects ingested 30 g glucose or a mixture of 25 g fructose and 5 g sorbitol as 10% solutions. As a radiolabeled marker, (99m)Tc-diethylenetriaminepentaacetic acid was added to each test solution. Breath hydrogen and methane concentrations and gastrointestinal progress of the radiolabeled marker were followed for the next 6-hr period. Malabsorption of small amounts of the fructose-sorbitol mixture was evident in all subjects. The area under the gastric radioactivity-time curve after ingestion of glucose did not differ from that after ingestion of the fructose-sorbitol mixture (P = 0.7897). However, the mouth-to-cecum transit of the radiolabeled marker was faster (P = 0.0033) and the percentage content of the marker in colon was higher after ingestion of the fructose-sorbitol mixture than after ingestion of glucose (P = 0.0128). In healthy humans, malabsorption of small amounts of a fructose-sorbitol mixture accelerates small bowel transit.
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PMID:Effect of nonabsorbed amounts of a fructose-sorbitol mixture on small intestinal transit in healthy volunteers. 1641 28

Sugars normally are absorbed in the small intestine. When carbohydrates are malabsorbed, the osmotic load produced by the high amount of low molecular weight sugars and partially digested starches in the small intestine can cause symptoms of intestinal distention, rapid peristalsis, and diarrhea. Colonic bacteria normally metabolize proximally malabsorbed dietary carbohydrate through fermentation to small fatty acids and gases (ie, hydrogen, methane, and carbon dioxide). When present in large amounts, the malabsorbed sugars and starches can be excreted in the stool. Sugar intolerance is the presence of abdominal symptoms related to the proximal or distal malabsorption of dietary carbohydrates. The symptoms consist of meal-related abdominal cramps and distention, increased flatulence, borborygmus, and diarrhea. Infants and young children with carbohydrate malabsorption show more intense symptoms than adults; the passage of undigested carbohydrates through the colon is more rapid and is associated with detectable carbohydrates in copious watery acid stools. Dehydration often follows feeding of the offending sugar. In this review we present the clinical and current molecular aspects of disaccharidase digestion.
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PMID:Disaccharide digestion: clinical and molecular aspects. 1652 88

The "breath test" based on the measurement of gases in expired air are an alternative to the study of metabolic and functional alterations in gastroenterology. They are classified into two groups based on the molecule analyzed and if the substrate is isotopically labelled or not: H2 and/or CH4 test (malabsorption of sugars, bacterial overgrowth, etc.) and 13CO2 test (infection by H. pylori, exocrine pancreatic function, etc.).
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PMID:[Utility of "breath test" in diagnosis of digestive diseases]. 1675 Jan 6

OBJECTIVE. Intestinal infection with Giardia lamblia may lead to therapy-resistant, long-lasting post-giardiasis irritable bowel syndrome (IBS). We report two open pilot studies aiming to treat this condition, using either antibiotics or bacterio-therapy. MATERIAL AND METHODS. Twenty-eight patients with persistent abdominal symptoms, following clearance of G. lamblia infection, were investigated. Eighteen received treatment with rifaximin plus metronidazole (8-10 days) whereas 10 received a suspension of live faecal flora, installed into the duodenum during gastro-duodenoscopy. Customary abdominal symptoms and symptoms following a lactulose breath test were quantified by questionnaires. Hydrogen and methane production after lactulose were analysed in expired air and excretion of fat and short-chain fatty acids (SCFAs) was examined in faeces. RESULTS. As compared with pre-treatment values, total customary symptom scores were barely significantly reduced (p = 0.07) after antibiotics, but were highly significantly reduced (p = 0.0009) after bacterio-therapy. However, symptom improvement following bacterio-therapy did not persist 1 year later. Hydrogen breath excretion was slightly reduced after antibiotics, but not after bacterio-therapy. Compared with healthy persons, faecal excretion of fat was significantly increased in Giardia-cured patients. SCFAs were increased in the bacterio-therapy group, and were not influenced by therapy. CONCLUSIONS. Both antibiotics and bacterio-therapy were ineffective with respect to cure of post-giardiasis IBS. High faecal excretion of fat and SCFAs suggests that intestinal malabsorption of fat and carbohydrates may play a role in the IBS-like complaints of these patients.
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PMID:Antibiotic or bacterial therapy in post-giardiasis irritable bowel syndrome. 1982 94


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