Prebiotic ingestion does not improve gastrointestinal barrier function in burn patients

Prebiotics increase intestinal levels of health-promoting bacteria implicated in decreasing pathogen colonization, stimulating immune functions and stabilizing gut barrier functions, parameters which are altered in burn patients. We propose that regular intake of a prebiotic, oligofructose (OF), might help to improve the altered gastrointestinal (GI) permeability observed in burn patients. A randomized, double-blind, controlled clinical trial was carried out in 41 burn patients (mean burn surface area=17.1+/-8.2%) who ingested daily 6 g of oligofructose (OF group) or sucrose as placebo (Control group) during 15 days. Gastrointestinal permeability to sucrose and lactulose/mannitol (L/M) was evaluated on days 1 (before treatment) 3, 7, 14 and 21. A permeability test was also performed in 18 healthy subjects as controls. Thirty-one patients completed the protocol (dropout rate=24.4%). Healthy subjects had a basal sucrose excretion of 21.3 mg (14.0-32.5 mg) and a basal L/M ratio of 0.017% (0.009-0.022%). Sucrose excretion increased 5-fold and L/M ratio 4.4-fold in burn patients on day 1 and these high levels of marker excretion decreased significantly throughout the study (p=0.016 and 0.000001, respectively). No differences between the OF and Control groups were observed for sucrose excretion or L/M ratio. In conclusion, the normalization of gastrointestinal permeability is not accelerated by prebiotic intake.

Evaluation of a triple sugar test of colonic permeability in humans

AIM

Conventional dual sugar tests of intestinal permeability assess only the stomach and small intestine. A novel triple sugar method of assessing colonic permeability has recently been described in animals. This utilizes the non-fermented sweetener sucralose, in addition to conventional sugars. It has been postulated that this test enables the simultaneous assessment of small-intestinal and colonic barrier function in humans. The aim of this study was to evaluate the triple sugar test using healthy volunteers and ileostomists.

METHODS

Twenty-one healthy volunteers and 18 ileostomists underwent the triple sugar test. After an overnight fast, subjects drank a solution containing lactulose (5 g), rhamnose (1 g) and sucralose (5 g). Urine was collected for 0-5 h and 5-19 h. Urinary sugars were quantified using HPLC, and 5 and 24-h excretion calculated. Nineteen control subjects and 16 ileostomists also underwent a 51Cr-EDTA permeability test. Permeability data were presented as medians (IQR), and differences between groups analysed with Mann-Whitney U-tests.

RESULTS

Lactulose excretion and the 5-h lactulose/rhamnose (L/R) ratio were similar in controls and ileostomists [L/R ratio 0.024 (0.022-0.034) vs. 0.025 (0.022-0.035), P = 0.955]. Twenty-four hours excretion of sucralose was significantly higher in control subjects compared with ileostomists [1.41% (1.17-1.68) vs. 0.96% (0.64-1.2), P = 0.003]. The same pattern was seen with 51Cr-EDTA [2.73% (2.06-3.76) vs. 2.06% (1.55-2.71), P = 0.037] and with lactulose [0.52% (0.42-0.60) vs. 0.25% (0.16-0.35), P = 0.002].

CONCLUSIONS

Both sucralose and 51Cr-EDTA underwent significant colonic absorption. A significant amount of lactulose also appeared to be absorbed in the colon. This unexpected finding requires further study.

Studies on intestinal permeability of cirrhotic patients by analysis lactulose and mannitol in urine with HPLC/RID/MS

The method for separation and determination of lactulose (L) and mannitol (M) in urine was developed by HPLC with a refractive index detector (RID). The linearity ranged from 5 to 1000 microg/mL for L and M, respectively. Recoveries ranged from 93.1% to 97.1%. The intra- and inter-day relative standard deviations of peak area were between 0.8-1.4% (n=3) and 1.4-3.6% (n=3). The limits of detection were obtained with 1.40 microg/mL for L and 1.65 microg/mL for M. The ratios of L/M in the urine samples for the spontaneous ascitic fluid infection (SAI), sterile ascitic fluid (SA) patients, and healthy volunteers (HV) were determined. The results showed well the correlations among the L/M ratio, intestinal permeability (IP) and the illness status of patients, and also indicated lactulose could improve the IP of SAI patients. The peaks of L and M in chromatograms were identified by electrospray ionization/mass spectrometry (ESI/MS), which ensured the accurate measurement of the ratio L/M. This method presented a rapid, accurate, and practical technique for determining IP in clinical practice and investigating the pathology of hepatocirrhosis.

Gut permeability in paediatric cardiac surgery

BACKGROUND

Intestinal mucosal ischaemia can occur in infants and children during and after cardiac surgery. Severe decreases in mucosal perfusion may cause complications such as necrotizing enterocolitis and postoperative mortality. We investigated gut permeability in paediatric patients undergoing cardiac surgery using the dual sugar permeability test and absorption of two other saccharides.

METHODS

Thirty-four patients undergoing palliative or corrective surgical procedures with and without cardiopulmonary bypass were investigated. Intestinal permeability was measured using 3-O-methyl-D-glucose, D-xylose, L-rhamnose and lactulose, given orally after induction of anaesthesia and 12 and 24 h later.

RESULTS

Lactulose/rhamnose ratios were raised from the outset [median 0.39 (confidence interval 0.07-1.8 for patients undergoing operations without cardiopulmonary bypass and 0.30 (0.02-2.6) with cardiopulmonary bypass]. The highest lactulose/rhamnose ratios were recorded 12 h after surgery 0.32 (0.07-6.9), when cardiopulmonary bypass was used. This is approximately seven times the value expected in healthy children. There was an improvement in patients not undergoing cardiopulmonary bypass: 0.22 (0.03-0.85) 12 h and 0.11 (0-0.48) 24 h after induction of anaesthesia. Patients undergoing repair of aortic coarctation showed the fastest recovery: 0.09 (0.03-0.31) 12 h and 0.07 (0.04-0.35) 24 h after induction of anaesthesia.

CONCLUSIONS

Patients with congenital heart defects have abnormal gut permeability when compared with healthy children of similar age. Cardiopulmonary bypass seems to affect the intestinal barrier morphologically (lactulose and rhamnose absorption) and functionally (3-O-methyl-D-glucose and D-xylose absorption).

Effect of glutamine on change in early postoperative intestinal permeability and its relation to systemic inflammatory response

AIM: To study the effects of glutamine (Gln) on the change of intestinal permeability and its relationship to systemic inflammatory response in early abdominal postoperative patients.

METHODS: A prospective, randomized, double-blind and controlled trial was taken. Twenty patients undergoing abdominal surgery were randomized into Gln group (oral administration of glutamine, 30 g/d, for 7 d, n = 10) and placebo group (oral administration of placebo, 30 g/d, for 7 d, n = 10). Temperatures and heart rates of all patients were daily recorded. White blood cell counts (WBC) and biochemical variables were measured before operation and 4 and 7 d after drug administration. Serum concentrations of glutamine, endotoxin, diamine oxidase and malondialdehyde and urine lactulose/mannito (L/M) ratio were measured before and 7 d after drug administration.

RESULTS: The patients in the 2 groups were comparable prior to drug administration. Serum Gln concentration was significantly decreased in the placebo group and increased in the Gln group 7 d after drug administration. Urine L/M ratio was significantly increased in the placebo group and decreased in the Gln group. The serum concentration of endotoxin, diamine oxidase and malondialdehyde was significantly decreased in the Gln group compared with those in the placebo group. Temperatures, heart rates and WBC counts were significantly lower in the Gln group than those in the placebo group.

CONCLUSION: Gut is one of the sources of systemic inflammatory response in abdominal postoperative patients and glutamine can decrease intestinal permeability, maintain intestinal barrier and attenuate systemic inflammatory response in early postoperative patients.

Effects of enteral supplementation with glutamine granules on intestinal mucosal barrier function in severe burned patients

Glutamine is an important energy source in intestinal mucosa, the small intestine is the major organ of glutamine uptake and metabolism and plays an important role in the maintenance of whole body glutamine homeostasis. The purpose of this clinical study is to observe the protection effects of enteral supplement with glutamine granules on intestinal mucosal barrier function in severe burned patients. Forty-eight severe burn patients (total burn surface area 30-75%, full thickness burn area 20-85%) were randomly divided into two groups: burn control group (B group, 23 patients) and glutamine treated group (Gln group, 25 patients). Glutamine granules 0.5 g/kg were supplied orally for 14 days in Gln group, and the same dosage of placebo were given for 14 days in B group. The plasma level of glutamine, endotoxin and the activity of diamine oxidase (DAO), as well as intestinal mucosal permeability were determined. The results showed that the levels of plasma endotoxin, activity and urinary lactulose and mannitol (L/M) ratio in all patients were significant higher than that of normal control. After taking glutamine granules for 14 days, plasma glutamine concentration was significantly higher in Gln group than that in B group (607.86+/-147.25 microM/l versus 447.63 +/- 132.28 microM/l, P < 0.01). On the other hand, the levels of plasma DAO activity and urinary L/M ratio in Gln group were lower than those in B group. In addition, the wound healing was better and hospital stay days were reduced in the Gln group (46.59 +/- 12.98 days versus 55.68 +/- 17.36 days, P < 0.05). These results indicated that glutamine granules taken orally could abate the degree of intestine injury, lessen intestinal mucosal permeability, ameliorate wound healing and reduce hospital stay.

Recombinant human lactoferrin ingestion attenuates indomethacin-induced enteropathy in vivo in healthy volunteers

OBJECTIVE

To determine whether recombinant human lactoferrin ingestion inhibits nonsteroidal antiinflammatory drugs (NSAID)-induced gastroenteropathy in vivo in healthy volunteers as a model for disorders associated with a rise in permeability of the stomach and the small intestine.

DESIGN

A randomized crossover dietary intervention.

SUBJECTS AND INTERVENTIONS

In all, 15 healthy volunteers (age 23+/-1.4 y) were tested. A sucrose and a lactulose/rhamnose (L/R) permeability test was performed to assess gastroduodenal and small intestine permeability as indicator of NSAID-induced gastroenteropathy. All subjects consumed standardized meals for 2 days. On the second day at time=-24 h each subject ingested a drink containing 5 g recombinant human lactoferrin or placebo during breakfast. At t=-9 h, subjects ingested the same drink with 75 mg of the NSAID indomethacin and after an overnight fast at t=-1 h subjects consumed the drink and 50 mg indomethacin. After 1 h, at t=0, a permeability test was performed.

RESULTS

Small intestine permeability after indomethacin and placebo was significantly higher (L/R ratio=0.036; 0.014-0.092, P<0.05) compared to the permeability observed after ingestion of indomethacin and lactoferrin (0.028; 0.015-0.056), whereas gastroduodenal permeability did not differ between the two interventions (P=0.3).

CONCLUSION

Oral recombinant human lactoferrin supplementation during a short-term indomethacin challenge reduced the NSAID-mediated increase in small intestinal permeability and hence may provide a nutritional tool in the treatment of hyperpermeability-associated disorders.

SPONSORSHIP

Grant and human recombinant lactoferrin donated from Agennix Inc., Houston, TX.

[Intestinal permeability of patients with advanced digestive tract malignant tumors]

OBJECTIVE

To assess the intestinal barrier function of patients with advanced digestive tract malignant tumors by measuring the changes in intestinal permeability.

METHODS

Sixteen patients with digestive tract tumors and 16 healthy volunteers were enrolled. After oral administration of mannitol and lactulose in deionized water, the 6-hour urine samples were collected for analyzing mannitol and lactulose concentrations using gas-liquid chromatography.

RESULTS

Urine lactulose concentration and lactulose/mannitol (L/M) ratio of the tumor patients were increased in comparison with those of the healthy subjects (P<0.05).

CONCLUSION

he intestinal permeability increased in these tumor patients, indicating intestinal barrier dysfunction.

Effect of early enteral nutrition on intestinal permeability, intestinal protein loss, and outcome in dogs with severe parvoviral enteritis

A randomized, controlled clinical trial investigated the effect of early enteral nutrition (EN) on intestinal permeability, intestinal protein loss, and outcome in parvoviral enteritis. Dogs were randomized into 2 groups: 15 dogs received no food until vomiting had ceased for 12 hours (mean 50 hours after admission; NPO group), and 15 dogs received early EN by nasoesophageal tube from 12 hours after admission (EEN group). All other treatments were identical. Intestinal permeability was assessed by 6‐hour urinary lactulose (L) and rhamnose (R) recoveries (%L, %R) and L/R recovery ratios. Intestinal protein loss was quantified by fecal α₁‐proteinase inhibitor concentrations (α₁‐PI). Median time to normalization of demeanor, appetite, vomiting, and diarrhea was 1 day shorter for the EEN group for each variable. Body weight increased insignificantly from admission in the NPO group (day 3: 2.5±2.8% day 6: 4.3±2.3% mean ± SE), whereas the EEN group exhibited significant weight gain (day 3: 8.1±2.7% day 6: 9.7 ± 2.1%). Mean urinary %L was increased, %R reduced, and L/R recovery ratios increased compared to reference values throughout the study for both groups. Percent lactulose recovery decreased in the EEN group (admission: 22.6±8.0% day 6: 17.9 ± 2.3%) and increased in the NPO group (admission: 11.0±2.6% day 6: 22.5 ± 4.6%, P= .035). Fecal α₁‐PI was above reference values in both groups and declined progressively. No significant differences occurred for %R, L/R ratios, or α₁‐PI between groups. Thirteen NPO dogs and all EEN dogs survived (P= .48). The EEN group showed earlier clinical improvement and significant weight gain. The significantly decreased %L in the EEN versus NPO group might reflect improved gut barrier function, which could limit bacterial or endotoxin translocation.

Green banana and pectin improve small intestinal permeability and reduce fluid loss in Bangladeshi children with persistent diarrhea

To evaluate the effects of green banana and pectin (nondigestible, dietary sources of colonic shortchain fatty acids [SCFA]) on intestinal permeability, 57 boys (5-12 months) with persistent diarrhea (> or = 14 days) were given a week's treatment with a rice-based diet containing either cooked green banana (n = 19), pectin (n = 17), or rice diet alone (n = 21). Intestinal permeability was assessed before and after treatment by giving a lactulose-mannitol (LM) drink and measuring urinary recovery after 5 hr. Treatment with banana significantly (P < 0.05) reduced lactulose recovery, increased mannitol recovery, and decreased the LM ratio, indicating improvement of permeability. Pectin produced similar results. Permeability changes were associated with a 50% reduction in stool weights which correlated strongly (green banana, r2 = 0.84, pectin, r2 = 0.86) with the LM ratio. Green banana-derived and SCFA-mediated stimulation of colonic as well as small bowel absorption is responsible for their antidiarrheal effects. The antidiarrheal effects of green banana and pectin are mediated by improvement of small intestinal permeability in addition to their known colonotrophic effects.

Intestinal permeability is decreased in anorexia nervosa

Malnutrition and absence of exogenous luminal nutrients in the gastrointestinal tract affect intestinal permeability (IP) leading to an increased penetration of substances that passively cross intestinal epithelium via intercellular pathways. We hypothesised that an increase in IP could occur in patients with anorexia nervosa because of their prolonged fasting and chronic malnutrition. Therefore, we assessed IP in 14 drug-free anorexic women and 19 drug-free age-matched healthy women by means of the lactulose/mannitol (LA/MA) test. To this purpose, after an overnight fast, subjects ingested an oral solution containing 5 g lactulose and 2 g mannitol in 100 ml water. Urine specimens were collected immediately before and 30, 60, 120, 180, 240 and 300 min after the ingestion of the sugar solution. Urinary lactulose and mannitol were determined by high-performance anion exchange chromatography coupled with pulsed amperometric detection. We found that IP, as expressed by the 5-h LA/MA excretion ratio, was significantly decreased in anorexic women because of a lower urinary recovery of lactulose. Moreover, in patients, the time course of lactulose excretion significantly differs from healthy controls. These results do not confirm our hypothesis of increased IP in anorexia nervosa. Since IP reflects the anatomo-functional status of intestinal mucosa, the present findings support the idea that changes in the anatomo-physiology of intestinal mucosa occur in anorexia nervosa.

Intestinal permeability to lactulose and mannitol in growing rats with iron-deficiency anemia

Iron deficiency can have nonhematological manifestations, some of which may affect the gastrointestinal tract. The aim of this study was to determine if iron-deficiency anemia in growing rats affected small-bowel permeability as assessed by the urinary ratio of lactulose and mannitol. Thirty-seven male Harlan Sprague-Dawley rats (21 d of age) were randomly divided into two groups and fed either an iron-deficient (n=19) or an iron-sufficient diet (n=18) that contained either 13.5 or 43.8 mg of iron/kg diet, respectively. Animals were evaluated between 25 and 38 d of dietary treatment. Intestinal permeability was assessed by measuring the lactulose/mannitol urinary ratio following administration of a solution that contained the two sugars. At the end of the study, the mean body weight of rats fed the low-iron diet was approx 95% that of the controls. The mean hemoglobin (g/dL) was significantly lower in the low-iron diet group (11.2+/-1.4) than in the control group (16.9+/-0.8) (p=0.001). The liver iron concentration (microg/g) of the anemic group (41.4+/-4.7) was also statistically (p=0.001) lower than in the control group (116.6+/-18.2). The lactulose/mannitol ratio was lower in the anemic rats (2.0+/-0.7) than in the control group (2.6+/-0.7) (p=0.008), a finding that is not suggestive of intestinal mucosal atrophy, previously described in anemic children.

Weaning to hypoallergenic formula improves gut barrier function in breast-fed infants with atopic eczema

OBJECTIVES

Infants may be sensitized to dietary antigens even during exclusive breast-feeding. Because food antigen traces in breast milk may have harmful effects on gut barrier function in infants with atopy, the authors sought to evaluate whether or not it is beneficial to shift such infants from breast milk to a hypoallergenic formula.

METHODS

Fifty-six infants (mean age, 5.0 months) manifesting atopic eczema during exclusive breast-feeding were studied at weaning to a tolerated hypoallergenic formula. The urinary recovery ratios of orally administered lactulose and mannitol, fecal alpha-1 antitrypsin and urinary methylhistamine, and eosinophil protein X concentrations were assessed during breast-feeding and after weaning.

RESULTS

The median (interquartile range, IQR) concentration of fecal alpha-1 antitrypsin was 2.3 mg/g (range, 1.2-3.3 mg/g) during breast-feeding and 0 (0.0-1.9 mg/g) after weaning to a tolerated hypoallergenic formula, z = -4.23, P < 0.0001. The urinary recovery ratio of lactulose and mannitol decreased from 0.029 (range, 0.021-0.042) to 0.023 (range, 0.016-0.031), respectively, z = -3.45, P = 0.0006. Concomitantly, the atopic eczema improved, and the concentration of urinary eosinophil protein X decreased significantly.

CONCLUSIONS

In breast-fed infants with atopy, gut barrier function is improved after cessation of breast-feeding and starting of hypoallergenic formula feeding.

Simultaneous gas-chromatographic measurement of rhamnose, lactulose and sucrose and their application in the testing gastrointestinal permeability

BACKGROUND

As it is important to test gastric and intestinal permeability simultaneously in gastrointestinal disorders such as Celiac disease, we developed a gas-chromatographic (GC) method to estimate rhamnose (L-rh), lactulose (Lacl) and sucrose (Suc) in urine.

METHODS

The method is based on the use of alditol acetate derivatives giving a lower number of GC peaks than reducing sugars do. Acetate derivatives are more stable and less expensive than GC silylates and keep the flame-detector cleaner. We checked the chemical stability of alditol acetates by verifying the reproducibility of the standard curve of a sugar derivative sample which had been stored for 2 months at -20 degrees C.

RESULTS

The calibration proved linear over the range 0.1-1 microg of sugar injected. Analytical sugar recovery was 88%+/-19.4% (mean+/-S.D.) for rhamnose, 105%+/-7.4% for sucrose and 102%+/-2.4% for lactulose. Mean within-day precision (CV) was 7.7% for rhamnose, 5.7% for sucrose and 1.9% for lactulose, and between-day (CV) was 6.7% for rhamnose, 3.9% for sucrose and 1.6% for lactulose. The rhamnose, lactulose and sucrose as the lactulose/rhamnose ratio clearly differentiated 25 healthy controls from 36 patients with active gluten-sensitive enteropathy.

CONCLUSIONS

A fast, reliable and cheap gas-chromatographic method is presented here to evaluate gastric and intestinal permeability.

Association of vitamin A and zinc status with altered intestinal permeability: analyses of cohort data from northeastern Brazil

To examine the association of intestinal barrier function with vitamin A deficiency and whether supplementation of micronutrients improves intestinal function and/or linear growth, height-for-age z-score (HAZ), concentrations of serum retinol and zinc, and intestinal permeability were determined in a cross-sectional sample of 75 children in northeastern Brazil. Effects of vitamin A and supplementation of zinc on intestinal permeability and growth were also determined comparing results before and after treatment in 20 children and age-matched controls. Lactulose:mannitol (L/M) permeability ratios inversely correlated with serum retinol concentrations (r = -0.55, p < 0.0005). Increased L/M permeability ratios with reduced concentrations of serum retinol were predominantly attributable to lower absorption of mannitol (r = 0.28, p = 0.02). L/M permeability ratios (p = 0.001) and HAZ scores (p = 0.007) improved with supplementation. It is concluded that impaired intestinal barrier function and linear growth shortfalls improve following supplementation of vitamin A and zinc in this setting.

Kinetics and postmucosal effects on urinary recovery of 5 intravenously administered sugars in healthy cats

The objective of this study was to describe the kinetics of urinary recovery and to evaluate the effects of postmucosal factors on urinary recovery of 5 intravenously administered saccharides. Ten cats received an isotonic sugar solution containing lactulose, rhamnose, xylose, methylglucose, and sucrose intravenously. These sugars were selected because of their prior use for intestinal permeability and mucosal function testing in humans and dogs. Urethral catheterization with a closed collection system was used for collection of cumulative urine samples prior to and 2, 4, 6, 8, 10, 12, and 24 h after administration of the sugar solution. High-pressure anion exchange liquid chromatography with pulsed amperometric detection was used to measure the concentrations of each sugar in the urine and calculate urinary recovery. Twenty-four hour cumulative urinary recovery for each sugar from the cats, was lower than expected compared to dogs and humans. All 5 sugars had the highest percentage of urinary recovery during the first 2 h after administration. Mean sugar elimination rate constants and half-lives ranged from 0.268/h for methylglucose to 0.415/h for lactulose and 1.67 h for lactulose to 2.59 h for methylglucose, respectively. Metabolism and incomplete urine collection are possible reasons for lower cumulative urinary recoveries of these 5 sugars in cats compared with dogs. Although these 5 sugars are not ideal marker molecules, they may still be useful for intestinal permeability and mucosal function testing in cats.

In vivo influence of nicotine on human basal and NSAID-induced gut barrier function

BACKGROUND

Smoking reduces the non-steroidal anti-inflammatory drug (NSAID)-induced small intestinal permeability increase in healthy people. It also affects inflammatory bowel disease that is associated with a disturbed gut barrier function. To assess the role of nicotine on barrier function, its influence on basal and NSAID-induced intestinal permeability was studied in healthy volunteers.

METHODS

Thirty-one healthy non-smoker subjects performed permeability tests with 51Cr-EDTA and sugar markers (sucrose, lactulose, mannitol, sucralose) before and during 2 weeks of nicotine patch application, and with and without indomethacin intake, respectively. Since smoking has been described as affecting motility, transit measurements were also done with the sodium[13C]-octanoate and lactose-[13C]-ureide breath tests before and during nicotine exposure. Correlations between permeability markers were checked and the influence of gastrointestinal transit was assessed.

RESULTS

Nicotine did not affect barrier function in vivo, nor gastric emptying, small-bowel transit time or orocaecal transit. 51Cr-EDTA and lactulose correlated in basal 0-6 h permeability testing (r = 0.529, P < 0.0001), as did 6-24 h excretion of 51Cr-EDTA and sucralose (r = 0.474, P < 0.001); 97% and 90% of the subjects had a permeability increase after indomethacin intake for 0-6 h and 6-24 h excretion of Cr-EDTA, respectively. This population proportion is 63% for lactulose/mannitol and 83% for sucralose.

CONCLUSIONS

Short-term exposure to nicotine does not alter normal basal or NSAID-induced gut barrier function or transit. 51Cr-EDTA and the respective sugar markers correlate well in in vivo permeability testing in healthy humans. The radioactive test detects more NSAID-induced permeability increase than does the lactulose/mannitol ratio permeability test.

Intestinal permeability and absorption in dogs with traumatic injury

The objectives of this study were to assess the feasibility of using urinary recovery of sugars to evaluate intestinal permeability and absorption in dogs with traumatic injury and to determine if intestinal permeability and absorption are altered in dogs with traumatic injury. After a 6-hour fast, a sugar solution containing lactulose, rhamnose, 3-0-methyl-D-glucose, and xylose was administered via nasoesophageal tube. Urine was collected and quantitated over the 6-hour study period via closed collection urinary catheters. Urinary sugar recoveries were measured by high-pressure anion exchange liquid chromatography and pulsed amperometric detection. Urinary sugar recoveries in the trauma group at 24, 48, and 72 hours after trauma were compared to normal controls. In addition, severity of trauma was compared to urinary sugar recoveries. Twelve client-owned dogs with traumatic injury and 6 healthy controls were enrolled in the study. Lactulose recovery and the lactulose:rhamnose recovery ratio were significantly higher in the trauma group at 48 hours but were no longer different from controls by 72 hours. Xylose recovery was significantly higher in the trauma group when compared to controls at 72 hours, whereas 3-O-methyl-D-glucose recovery was significantly lower in the trauma group at 24 hours. The xylose: 3-O-methyl-D-glucose ratio was higher in the trauma group at all time points. Significant correlation was found between severity of trauma and xylose and 3-O-methyl-D-glucose recoveries 24 hours after injury. Results of this study support the hypothesis that intestinal permeability and absorption are altered in dogs with traumatic injury.

Mucosal pathology of the upper gastrointestinal tract associated with intensive chemotherapy in children: vitamin A supplements do not prevent lesions

Intensive chemotherapy (ICT) for a malignant disease in children may be associated with clinically significant mucosal lesions of the upper gastrointestinal tract. This prospective and randomized study was conducted to evaluate more thoroughly the mucosal damage and to find out whether vitamin A therapy might prevent the development of these lesions. Gastroduodenoscopy and non-invasive methods were used to examine a consecutive series of 20 patients (10 females, 10 males, aged 1-15 years) 4 weeks after initiating the therapy regimen. Half of the patients were randomized to take vitamin A supplements for 6 weeks. During a follow-up of 6 weeks, 13 (65%) reported some symptoms of the gastrointestinal (GI) tract, diarrhea and mouth pain being most prominent. Endoscopic abnormalities were found in 13 (65 %) subjects: esophagitis in 10, erosive duodenitis in 8, and gastritis in 7. Histologically, 11 subjects had duodenitis, 5 had gastritis, 3 had eosinophilic esophagitis, and 2 had lymphocytic esophagitis. Both endoscopic and histological abnormalities of the duodenum showed a close relationship with long-term (more than 2 weeks) granulocytopenia. The 4 patients with the most extensive endoscopic abnormalities were treated with HCl inhibitors, and re-endoscopy performed 4-8 weeks later showed complete recovery. The sugar permeability values, measured as the lactulose/mannitol ratio were comparable to the values obtained in the controls, and lactose intolerance was found in only 3 (20%) of the 15 children able to perform the breath test. Both the incidence of the reported GI symptoms and the endoscopically or histologically observed GI lesions were similar in the subjects randomized to take vitamin A supplements as in the controls. In this study, two-thirds of children with ICT showed erosive mucosal lesions of the upper gastrointestinal tract, and vitamin A therapy failed to prevent them. Endoscopic examination is recommended if a patient has severe symptoms indicative of mucosal pathology.

Effect of acute copper exposure on gastrointestinal permeability in healthy volunteers

In vitro studies indicate that treating cells with copper results in alteration of tight junction permeability. In humans, ingestion of a single bolus of up to 10 mg Cu/L (as copper sulfate) causes nausea and vomiting in approximately 20 and 5% of the volunteers, respectively. To understand better the gastric and intestinal effects of copper, in this study we evaluated in asymptomatic volunteers (1) the effects of acute copper ingestion on gastric and intestinal permeability and (2) whether the appearance of gastrointestinal symptoms is associated with changes in mucosal permeability. Thirty-one asymptomatic subjects were assessed in a randomized, double-blind, crossover study that included two permeability tests, one after ingesting 200 ml distilled water and the other after ingesting 200 ml water containing 10 mg Cu/L (as copper sulfate). Fifteen minutes after ingestion subjects drank a second solution containing 40 g sucrose, 7.5 g lactulose, and 2 g mannitol, and urine was collected for 5 hr. Sugar concentrations were determined by gas chromatography. Symptoms during the trials were recorded in self-administered questionnaires. Ingestion of the 10 mg/L copper solution significantly increased gastric permeability to sucrose [20.8 (11.8-73.4) vs 28.4 (16.6-113.9) mg, respectively; P = 0.0064] but did not change intestinal permeability to lactulose/mannitol [0.87 (0.53-2.06) vs 1.17 (0.58-2.39)%, respectively; P = 0.18]. Gastrointestinal symptoms were reported during both the basal and the experimental conditions, but after copper ingestion they increased to 22.6% of the subjects and were significantly more intense than under basal conditions (P = 0.047). However, changes in permeability were not related to the appearance of symptoms. These results indicate that acute oral exposure to 10 mg Cu/L exerts an effect on gastric but not intestinal mucosa, reducing the gastric mucosal barrier capacity, independently of the appearance of gastrointestinal symptoms.

Intestinal permeability testing using lactulose and rhamnose: a comparison between clinically normal cats and dogs and between dogs of different breeds

In the experiment reported here, the lactulose/rhamnose urinary excretion test was used to compare intestinal permeability between four breeds of healthy adult dogs and a group of healthy adult cats. A significant difference in permeability was found between dogs and cats (P <0.001) and between different breeds of dogs (P <0.005). The range of urinary lactulose/rhamnose ratios in the dogs in this study (0.07-0.61) was wider than previously reported (0.03-0.12). The mean value for dogs was 0.19. The range in cats was 0.41-1.25 and the mean 0.52. The results of this study suggest that breed or some other factor such as environment, diet or sexual status as well as species should be taken into account when assessing intestinal permeability using the lactulose/rhamnose urinary excretion test.

Intestinal permeability in patients with chemotherapy-induced stomatitis

PURPOSE

Mucositis represents one of the most common side effects of chemotherapy, and may affect any part of the gastrointestinal tract, resulting in stomatitis, dysphagia, dyspepsia, or diarrhea. The aim of the present study was to evaluate intestinal permeability in patients with stomatitis during treatment with oral granulocyte-monocyte colony-stimulating factor (GM-CSF, Leucomax).

METHODS

Ten patients with chemotherapy-induced stomatitis and 21 control cancer patients were included in the study. Intestinal permeability in patients with stomatitis was evaluated before and after the treatment with oral GM-CSF (200 micrograms for 4 consecutive days) by measuring urinary lactulose, D-xylose, and mannitol after oral challenge in collected urine using capillary gas chromatography.

RESULTS

Mean grade of stomatitis (3, range 2-3) improved during treatment by a mean of 1 grade (range 0-2, sign test P < 0.05) with an improvement observed in eight of ten patients. Lactulose excretion, lactulose/mannitol, and lactulose/xylose ratios were markedly elevated in the patients with mucositis compared with 21 control cancer patients (1.60 +/- 1.04%, 0.2446 +/- 0.2937, and 0.3877 +/- 0.6808 vs 0.35 +/- 0.20%, 0.0332 +/- 0.0148, and 0.0255 +/- 0.0086, respectively, Mann Whitney U-test, P < 0.001). After treatment, lactulose excretion, lactulose/mannitol, and lactulose/xylose ratio decreased significantly (1.60 +/- 1.04 vs 0.63 +/- 0.42%; 0.2446 +/- 0.2937 vs 0.1303 +/- 0.1149; and 0.3877 +/- 0.6808 vs 0.1126 +/- 0.1146, respectively, P < 0.05).

CONCLUSIONS

Lactulose excretion after oral challenge, lactulose/mannitol, or lactulose/xylose ratio may be useful markers for intestinal involvement in chemotherapy-induced mucositis. Improvement of oral mucositis was associated with a significant decrease of intestinal permeability to lactulose. Testing of intestinal permeability by the present method may be useful to evaluate the effect of therapeutic interventions in patients with chemotherapy-induced mucositis.