Urinary Excretion Of D-xylose Research Articles

Small intestinal enteropathy in undernourished children in three urban slums in South India

Introduction: Growth faltering is a common health issue in the developing countries. At times we are unable to attribute this growth faltering to lack of adequate nutrients in food or ongoing disease conditions alone. With this study we aim to assess the possibility of the existence of subclinical malabsorption in children with undernutrition. Methods: A cross sectional study was conducted on a sample of 161 children from a birth cohort of 377 children who were under follow up from birth for health and disease in three of the urban slums of Vellore. The prevalence of small intestinal enteropathy, as assessed by a 5 hour urinary d-xylose excretion test, was compared between undernourished and well-nourished children. Correlation between undernutrition, d-xylose malabsorption and previous documented illnesses including viral, bacterial or parasitic infections/ infestations was also studied. Results: Xylose test result was abnormal in 41% (25 of 61) of undernourished children as against 26% (26 of 100) of well-nourished children, with p value of 0.047 and Odds ratio of 1.976 with 95% confidence interval between 1.003 and 3.895. Conclusion: There is a statistically significant association between undernutrition and small intestinal enteropathy

The Effect of Bariatric Surgery on Intestinal Absorption and Transit Time

Bariatric surgical procedures are classified by their presumed mechanisms of action: restrictive, malabsorptive or a combination of both. However, this dogma is questionable and remains unproven. We investigated post-operative changes in nutrient absorption and transit time following bariatric surgery. Participants were recruited into four groups: obese controls (body mass index (BMI) >30 kg/m2, n = 7), adjustable gastric banding (n = 6), Roux-en-Y gastric bypass (RYGB, n = 7) and biliopancreatic diversion with duodenal switch (DS, n = 5). Participants underwent sulphasalazine/sulphapyridine tests (oro-caecal transit time); fasting plasma citrulline (functional enterocyte mass); 3 days faecal collection for faecal elastase 1 (FE-1); calprotectin (FCp); faecal fatty acids (pancreatic exocrine function, gut inflammation and fat excretion, respectively); and 5 h D-xylose, L-rhamnose and lactulose test (intestinal absorption and permeability). Age and gender were not different but BMI differed between groups (p = 0.001). No difference in oro-caecal transit time (p = 0.935) or functional enterocyte mass (p = 0.819) was detected. FCp was elevated post-RYGB vs. obese (p = 0.016) and FE-1 was reduced post-RYGB vs. obese (p = 0.002). Faecal fat concentrations were increased post-DS vs. obese (p = 0.038) and RYGB (p = 0.024) and were also higher post-RYGB vs. obese (p = 0.033). Urinary excretion of D-xylose and L-rhamnose was not different between the groups; however, lactulose/rhamnose ratio was elevated post-DS vs. other groups (all p < 0.02), suggesting increased intestinal permeability. Following RYGB, there are surprisingly few abnormalities or indications of severe malabsorption of fats or sugars. Small bowel adaptation after bariatric surgery may be key to understanding the mechanisms responsible for the beneficial metabolic effects of these operations.

Intestinal malabsorption of d-xylose: Comparison of test modalities in patients with celiac disease

Objective. The aim of the study was to compare three different D-xylose test modalities for small intestinal malabsorption, using patients with celiac disease and healthy persons as experimental models. Material and methods. Ninety-one untreated celiac patients, 98 treated celiac patients, and 43 healthy subjects performed the 13C-d-xylose breath test. 1-h plasma d-xylose levels were measured in 48 untreated patients, 41 treated patients and 41 healthy controls. 4-h urine d-xylose excretion was measured in 47 untreated patients, 51 treated patients and 42 healthy controls. 100 mg of 13C-d-xylose and 5 g of d-xylose were dissolved in 250 ml tap water and given orally. 13CO2 was measured in breath every 30 min for 4 h. Blood was sampled after 1 h, and urine collected after 4 h. Results. Test sensitivity/specificity for celiac disease was 88%/84% with the 13C-d-xylose breath test, 65%/71% with the 1-h plasma d-xylose test, and 55%/74% with the 4-h urine d-xylose excretion test. Breath test results improved significantly in the treated celiac group compared to untreated patients, but were not normalized compared to healthy controls. No difference was found between 1-h plasma d-xylose levels and 4-h urinary d-xylose excretion in treated celiac patients and healthy controls. Conclusions. The 13C-d-xylose breath test was superior to d-xylose testing in plasma and urine for assessment of small intestinal malabsorption with considerably higher sensitivity and specificity for untreated celiac disease.

Severe Acute Pancreatitis: The Life After

BackgroundThe present study reports functional and morphological changes noted over long-term follow-up in patients with severe acute pancreatitis. MethodsThirty patients who had completed at least 6 months after recovery were included. Fecal fat, urinary d-xylose, blood sugar, C-peptide, pancreatic changes, and recurrences were studied. ResultsEtiology was gallstones (12), alcohol (10), both gallstone and alcohol (3), and idiopathic (5). Five patients were managed conservatively while 25 underwent surgery. Mean follow-up was 31.3 months. Exocrine and endocrine insufficiencies were noted in 12 (40%) and were more common in no-necrosis group compared to necrosis group (p = 0.04 and 0.28, respectively) and infected compared to sterile pancreatitis (45% vs. 25%, p = 0.55 and 50% vs. 12%, p = 0.15, respectively). Higher frequency was noted in nonvisualized, partly visualized, and dilated segment of duct. Significant proportion (8/12) had both exocrine and endocrine abnormalities and their incidence decreased as duration of follow-up increased. Urinary d-xylose excretion was abnormal in 16% and noted >1 year postrecovery. Thirty percent required >1 readmission and pain was the commonest cause. ConclusionsForty percent had functional abnormality; 16% had mucosal absorption abnormality while 30% required >1 readmission. Exocrine and endocrine insufficiencies were more prevalent in first year, and a significant proportion had both. A trend for higher functional insufficiency was observed in infected necrosis, complete or incomplete visualization of main pancreatic duct (MPD), dilated segment of MPD, and pseudocyst.

Noninvasive Evaluation of Intestinal Lactase with 4-Galactosylxylose: Comparison with 3- and 2-Galactosylxylose and Optimization of the Method in Rats

Urinary excretion of D-xylose by suckling rats after ingestion of a mixture of 4-, 3-, and 2-galactosylxyloses reflects lactase activity in vivo. We aimed to select the most convenient of these disaccharides for detecting changes of the enzyme activity in vivo and to optimize the method. 4-, 3-, and 2-galactosylxyloses were synthesized and purified, then orally administered to suckling rats of different ages. D-Xylose was measured colorimetrically by the phloroglucinol reaction in urine and plasma. Lactase activity was determined in extracts of small intestine mucosa with lactose, galactosylxyloses, and phlorizin as substrates. D-Xylose appeared in the urine in a dose-dependent manner after ingestion of any of the 3 galactosylxylose disaccharides. Correlation between D-xylose elimination and intestinal lactase activity was highest with 4-galactosylxylose (r = 0.97; n = 24), lower with 2-galactosylxylose (r = 0.89; n = 24), and lowest with 3-galactosylxylose (r = 0.34; n = 23). The kinetic properties of intestinal lactase accounted for these differences. D-Xylose concentration in plasma after administration of 4-galactosylxylose also correlated with lactase activity (r = 0.93; n = 33). 4-Galactosylxylose is the most suitable compound for the evaluation of lactase activity in vivo. Measurement of the derived D-xylose in either urine or blood gives an estimate of the total lactose digestive capacity of the small intestine. The optimized method holds promise for development of a simple, low-cost, and reliable new test for the noninvasive diagnosis of hypolactasia.

Follow-up of celiac disease with D-xylose breath test.

Hydrogen breath tests (H2-BT) are commonly used to diagnose carbohydrate malabsorption. Specifically, the H2-BT with D-xylose has been shown to be as valid as the traditional urinary test for the recognition of intestinal malabsorption. We have now investigated the H2-BT with D-xylose in the follow-up of patients with celiac disease. Seventeen patients with celiac disease established clinically and confirmed by jejunal biopsy were studied. H2-BT was performed before and after treatment with a gluten-free diet for at least five months. Alveolar breath samples were obtained before administering orally 25 g of D-xylose and thereafter at 30 min intervals for 5 hr. Samples were analyzed for H2 by chromatography. Simultaneously, the 5-hr urinary excretion of D-xylose was determined by colorimetry. Gluten removal significantly decreased the H2 delta change (from 56.5 +/- 5.9 ppm to 32.2 +/- 8.8, P < 0.05). A similar decrease was observed in the area under the curve (P < 0.05). Conversely, urinary D-xylose excretion increased significantly (P < 0.05). Eleven of the 17 celiacs clinically improved after treatment. The H2-BT normalized in every patient who entered remission on the gluten-free diet, whereas the urinary D-xylose excretion remained abnormal in six of them. In the six nonresponder patients the H2-BT remained high in five, whereas urinary D-xylose excretion paradoxically normalized in 2. We conclude that H2-BT with D-xylose is a useful and practical test for the follow-up of celiac disease and is simpler and more reliable than the urinary D-xylose test.

Clinical applicability of shortenedd-Xylose breath test for diagnosis of intestinal malabsorption

Urinary and/or plasmatic D-xylose tests are broadly used in clinical practice for the diagnosis of intestinal malabsorption. A 5-hr hydrogen breath test (H2 BT) has also proven useful. Our goal was to determine whether a shorter, hence more efficient, 3-hr test would perform as well as the 5-hr test. We studied 33 patients with proven malabsorption, 44 patients with irritable bowel syndrome (IBS), and 27 healthy subjects. Each individual ingested 25 g of D-xylose, and alveolar breath samples were obtained thereafter at 30 min intervals for 5 hr. Breath samples were analyzed for H2 by gas chromatography. Individual peak delta changes and area under the curve (AUC) were calculated. Simultaneously, the 5-hr cumulative urinary excretion of D-xylose was measured by colorimetry. Results of 5-hr tests were compared with those of the first 3 hrs. In the malabsorption group, the 5-hr test showed a markedly enhanced production of H2 relative to healthy controls (delta: 60.7 +/- 6.4 vs 7.7 +/- 1.5 and AUC: 8465.0 +/- 985.4 vs 393.2 +/- 232.6, P < 0.001). Results in IBS patients did not differ from those in healthy controls. Three-hour analysis also reflected an enhanced production of H2 in the malabsorption group (delta: 45.4 +/- 6.4 and AUC: 3700.0 +/- 545.6, P < 0.001 vs healthy controls).(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetic analysis of D-xylose distribution after intravenous administration to mares

SUMMARY Multicompartmental analysis was applied to study the kinetics of D-xylose distribution after IV administration to healthy mares deprived of food for 12 and 96 hours. Urinary excretion of D-xylose was measured over a 15-hour period after administration. The plasma D-xylose concentrations in this study were in the range found after oral tolerance testing. The disposition of D-xylose was described by a two-compartment model with linear kinetic characteristics. Total volume of distribution decreased significantly (P &lt; 0.025) from 0.270 L/kg of body weight after the 12-hour period of food deprivation to 0.235 L/kg after the 96-hour period. Fractional rate of transfer between the central and peripheral compartments did not change after 96 hours without food. Approximately a third of the D-xylose administered was recovered in the urine. Difference in urinary elimination between the 12- and 96-hour periods was not significant. Nonrenal elimination rate was determined to be twice the renal elimination rate. The results indicated that formal kinetic analysis can provide useful information about D-xylose distribution in horses. The decreased D-xylose space found after a 96-hour period of food deprivation would tend to increase the plasma D-xylose concentration, and this may help in the interpretation of the D-xylose absorption test applied to anorectic horses.

4- O-β-spD-Galactopyranosyl-spD-xylose: A new synthesis and application to the evaluation of intestinal lactase

4- O-β-spD-Galactopyranosyl-spD-xylose ( 2) was prepared from benzyl 2,3- O-isopropylidene-β-spD-xylopyranoside by glycosylation with 2,3,4,6-tetra- O-benzoyl-α-spD-galactopyranosyl bromide and subsequent deprotection. Compound 2 was hydrolyzed in vitro by intestinal lactase; the V max was 25% of that with lactose and the K m was 370mspM cf. 27m m for lactose). Oral administration of 2 to suckling rats led to urinary excretion of d-xylose which would be estimated colorimetrically.

The utilization of orally administered d-xylose, l-arabinose and d-galacturonic acid in the pig

Measurements were made of the absorption up to the end of the ileum and of the urinary excretion of D-xylose, L-arabinose and D-galacturonic acid given to pigs. When given at a rate of 4g/day mean ileal digestibilities were 0.96 for xylose and 0.76 for both arabinose and galacturonic acid. Mean urinary excretion, as a proportion of the daily dose, was 0.35 for xylose, 0.42 for arabinose and 0.01 for galacturonic acid. When arabinose and galacturonic acid were given at a rate of 30 g/day mean ileal digestibilities were 0.56 and 0.34 respectively; the corresponding proportions of the dose excreted in the urine were 0.42 and 0.02. Indirect calorimetry was used to measure the heat increment associated with a single large dose of each carbohydrate. The mean proportion of the energy of these supplements which was retained amounted to 0.75 for xylose, 1.00 for arabinose and 0.75 for galacturonic acid.

Histopathologic Findings of Duodenal Biopsy Specimens in HIV-infected Patients With and Without Diarrhea and Malabsorption

The significance of the human immunodeficiency virus (HIV) in the small intestinal lamina propria in patients with the acquired immune deficiency syndrome or conditions related to that syndrome who have chronic diarrhea and malabsorption is unclear. To investigate this issue, upper endoscopy (after a 12- to 16-hour fast) with duodenal biopsy and aspirate was performed in 20 HIV-infected seropositive homosexual men referred for diarrhea of more than 8 weeks duration (Group 2) and in 9 HIV-infected homosexual men referred for dysphagia or dyspepsia with no symptoms of malabsorption (Group 1). All biopsy specimens were examined by light microscopy and immunochemical staining with monoclonal antibody against HIV glycoprotein gp41. Electron microscopy was performed in 18 patients in Group 2 and in all patients in Group 1. Immunogold electron microscopy was used as a confirmatory test for identified HIV particles. In addition, D-xylose absorption was measured in all patients after a 25-g dose of D-xylose with measurement of serum D-xylose concentration 1 hour after the dose and measurement of 5-hour urinary D-xylose excretion. Mean serum D-xylose was 35.4 +/- 4.5 mg/dL in Group 1 and 15.8 +/- 2.3 mg/dL in Group 2 (P less than 0.001), whereas mean urine D-xylose was 5.5 +/- 0.6 g in Group 1 and 2.0 +/- 0.4 g in Group 2 (P less than 0.001). Immunoperoxidase for gp41 was positive in 5 (56%) patients in Group 1 and in 12 (60%) patients in Group 2. Lamina propria HIV viral particles were identified by electron microscopy in both patient groups. Viral particles were seen within and adjacent to the cytoplasm of mononuclear cells and were not present in enterocytes or neuroendocrine cells. There were no significant differences in serum or urine D-xylose tests between patients with and without lamina propria HIV. In addition, lipid accumulation in intercellular spaces near the basolateral membrane of adjacent enterocytes was seen in 33% of patients with chronic diarrhea. These findings suggest that lamina propria HIV is not a direct cause of enteropathy in HIV-infected patients and that lymphatic obstruction may be one pathophysiologic mechanism producing this malabsorptive state.

Nutritional implications of D-xylose in pigs

Hemicellulose consists primarily of pentose sugars, joined together in a polysaccharide chain with D-xylose as the most abundant component. Ileal digestibility and urinary excretion of D-xylose and associated effects of this pentose sugar on ileal and faecal digestibility of dry matter (DM), organic matter (OM), gross energy (GE) and nitrogen were studied in pigs. Castrated pigs were prepared with a post-valvular T-caecum cannula to measure ileal digestibility. Faecal digestibility was measured in non-cannulated pigs. D-Xylose was given at dietary inclusion levels of 100 and 200 g/kg, and the control sugar, D-glucose, at a rate of 200 g/kg diet. Ileal digestibility of D-xylose as well as that of D-glucose was found to be close to 100%. The presence of D-xylose in the diet decreased ileal digesta pH and increased ileal flow of volatile fatty acids, suggesting the occurrence of microbial degradation of D-xylose in the pig small intestine. In pigs fed on the 100 g D-xylose/kg diet, 44.5% of the D-xylose intake appeared in the urine. This percentage increased significantly to 52.6 when pigs were fed on the 200 g D-xylose/kg diet. Ileal and faecal digestibility of DM, OM, GE and N, as well as N retention, decreased significantly in pigs fed on the 200 g D-xylose/kg diet.

Ileal Digestibility and Urinary Excretion of D-Xylose and L-Arabinose in Ileostomized Adult Roosters

An experiment with ileostomized adult roosters was conducted to determine the ileal digestibility and urinary excretion of D-xylose and L-arabinose. As a reference, D-glucose was included in the experiment. The sugars were tested at graded dietary levels of 2.5, 5.0, 7.5, and 10.0%. Mean ileal digestibility of D-glucose and D-xylose was nearly 100%. Ileal digestibility of L-arabinose decreased linearly (P<.05) with increasing dose level. The corresponding ileal digestibilities for L-arabinose at dietary levels of 2.5, 5.0, 7.5, and 10.0% were 95.5, 93.6, 80.3, and 74.6%. Both pentose sugars were partly excreted in the urine. The extent of this urinary excretion in percentage of intake increased linearly (P<.05) as the dietary level increased. In roosters fed the 2.5% D-xylose diet, 7.2% of the D-xylose consumed appeared in the urine. This level increased to 20.2% when roosters were fed a diet containing 10.0% D-xylose. Corresponding values for L-arabinose at these dietary inclusion levels were 8.7 and 16.6%.

New method of testing for carbohydrate absorption in man. Xylose and sucrose absorption; effects of sucrase inhibition.

Absorption of carbohydrate was quantitated in 49 subjects without disease of the small bowel using a new technique for ileal perfusion. A double-lumen tube with an attached balloon was inserted retrograde through the colon and used to quantify arrival in the ileum of D-xylose and a nonabsorbable marker which had been taken orally. In the same way, absorption of sucrose and the effects of an inhibitor of alpha-glucosidase were also studied. Insertion of the assembly through the colon and intubation of the terminal ileum was usually possible within 30 min; we have designated the technique, endoscopic retrograde bowel insertion (ERBI). The test meals were 500 ml of water containing either 25 g D-xylose and 5 g polyethylene glycol (PEG 4000), or 100 g sucrose with 5 g PEG. Sucrose meals also contained 0, 100, or 200 mg of an inhibitor of alpha-glucosidase (BAYg5421). At the end of a 5-hr test period, the ratio of recovery of D-xylose relative to that of PEG indicated that 69% of D-xylose was absorbed. Five-hour urinary excretion of D-xylose was 31% of that ingested, or 45% of the D-xylose which was absorbed. Sucrose was recovered in ileal samples only when administered together with inhibitor. Rates of sucrose absorption with BAYg5421, 100 and 200 mg, were 75% and 65%, respectively. The perfusion technique of ERBI is a rapid and reproduceable approach to the distal small intestine of man which could be of value in the investigation of intestinal absorption.

The intestinal mucosa in thyrotoxicosis: a light and electron microscopic assessment.

The intestinal mucosa was investigated by light and electron microscopic techniques in a group of 7 patients with thyrotoxicosis. Steatorrhoea was found in two patients and can be accounted for by other medical states. The intestinal mucosa was essentially normal in all seven cases including those with biochemical evidence of malabsorption. Urinary excretion of D-xylose and serum carotene have not been found to be reliable screening tests for malabsorption in thyrotoxicosis and possible explanations are discussed. It is concluded that thyrotoxicosisper se is not associated with structural alterations in the intestinal mucosa.

Impairment ofd-xylose absorption in Zambian patients with systemic bacterial infections

Urinary excretion of d-xylose during a 5-hr period after 25 g of the sugar was given orally has been estimated in 70 Zambian African men. Seventeen had pulmonary tuberculosis and sixteen had an acute bacterial infection. Six healthy Englishmen were also studied. The mean excretion of xylose in the tuberculosis (P< 0.001) and acute infection (P< 0.05) groups was significantly lower than that in Zambian patients without bacterial infections. Both groups with infections had a significantly lower excretion than the Englishmen. In the probable absence of renal disease, it seems likely that the results represent an impairment of xylose absorption in the presence of systemic bacterial infections. The reason for this impairment is not clear but it does not seem to be associated with altered jejunal morphology, which was studied in 17 of the patients. If dietary constituents are also poorly absorbed in the presence of systemic infection, this observation may explain part of the weight loss in patients with chronic bacterial infections. As patients with kwashiorkor often have evidence of a bacterial infection, it seems probable that systemic infections are an etiological factor in malnutrition.

Malabsorption in systemic lupus erythematosus.

A case of systemic lupus erythematosus (SLE) with intestinal malabsorption is reported. The malabsorptive state was manifested by steatorrhea, low blood levels, diminished urinary excretion ofd-xylose and reduced absorption-excretion of radioactive vitamin B12. The small-bowel mucosa showed blunted villi. Barium studies of the colon suggested infarction of the bowel. This is the fourth reported case in which SLE has been found to be associated with intestinal malabsorption.

D-XYLOSE ABSORPTION BEFORE AND AFTER PORTASYSTEMIC VENOUS ANASTOMOSIS

The 5-hour urinary excretion of D-xylose after an oral dose of 25 g. has been studied in a group of ten patients with portal hypertension, before and after portasystemic anastomosis, and in a control group of fifteen patients undergoing major surgery not involving the stomach or small intestine. Assuming a quantitative relation between absorption and excretion, it has been shown that the absorption of D-xylose may be depressed in the presence of portal hypertension, and that it was increased in all cases after portasystemic anastomosis. Follow-up studies up to nearly 3 years after operation indicate that this higher level is maintained while there is evidence that the anastomosis remains patent.

Distribution of d-xylose in sequestered fluid resulting in false-positive tests for malabsorption.

Blood levels and urinary excretion of D-xylose, after a 25-g oral load, were determined in 20 patients with cirrhosis. In all patients blood levels of xylose were above normal, and in 15 patients without ascites the urinary excretion of xylose was normal. In the other five cirrhotic patients with ascites and in two additional patients with ascites due to tuberculous peritonitis, the urinary excretion of xylose was markedly reduced. All of these seven patients with ascites had xylose in the ascitic fluid up to 23 hr. These results indicate that low 5-hr urinary excretion of xylose occurs in subjects with ascites, leading to a false-positive test for malabsorption.

Physiologic alterations in small bowel function with age. The absorption of D-xylose.

Studies of changes in xylose absorption with aging revealed that there was no difference in urinaryD-xylose excretion after a 25-gm. oral dose in subjects between the ages of 30 and 69. Xylose excretion decreased in subjects in the 70- to 79-year age group, and decreased even more among subjects over the age of 80. In addition, in the latter group, hourly blood xylose values were lower, reached peak levels later, and the blood disappearance rate was slower. These results suggest that in subjects over 80 there is decreased ability of the small bowel to absorb xylose and of the kidney to excrete xylose.