Can urinary indolylacroylglycine levels be used to determine whether children with autism will benefit from dietary intervention?

BACKGROUND: An increase in urinary indolyl-3-acryloylglycine (IAG) has been reported in children with autism spectrum disorders (ASD) who suffer with bowel problems in comparison to ASD children without gastrointestinal (GI) problems. The case for dietary intervention for ASD children with GI symptoms might be strengthened were such a difference to be autism-specific. METHODS: Quantitative analysis of urinary IAG levels was performed for 53 children on the autism spectrum and 146 age-matched controls. The parents of each child were asked to provide information on bowel symptoms experienced by the child and their eating habits over a period of 2 wk. RESULTS: We find no significant difference in urinary IAG levels between the ASD children with GI problems and ASD children without GI problems. Although we see some difference between ASD children with GI problems and controls in mainstream schools with GI problems, the difference between non-autistic children with other developmental disorders and controls in mainstream schools is more significant so that any difference is not autism-specific. We find a strong correlation between bowel symptoms and diet problems in ASD children, especially idiosyncratic feeding behavior and we show that ASD children suffering from multiple bowel symptoms tend to be those who also have dietary problems. CONCLUSION: We found no evidence to support the hypothesis that children with ASD who suffer with bowel problems have increased levels of urinary IAG in comparison to children with ASD who do not have gastrointestinal problems.

Abnormal gut integrity is associated with reduced linear growth in rural Malawian children.

The aim of the present study was to investigate the relation of environmental enteropathy, as measured by the dual sugar absorption test, to linear growth faltering in 2- to 5-year-old Malawian children. Dietary quality, food insecurity, anthropometry, and site-specific sugar testing were measured in 418 children, and anthropometry was reassessed 3 months later. A linear regression model predicting linear growth was created. Better growth was associated with less urinary lactulose excretion, more clean water usage, not sleeping with animals, and no previous history of malnutrition. Eighty-seven percent of children studied demonstrated evidence of environmental enteropathy. In conclusion, abnormal gut integrity is associated with reduced linear growth in a population of rural African preschool-age children.

Intestinal barrier dysfunction in liver cirrhosis assessed by iohexol test.

OBJECTIVE: To study gut barrier function in patients with liver cirrhosis (LC) by evaluating the intestinal permeability (IP) and its relationship with the severity and etiology of the disease. PATIENTS AND METHODS: The study included 31 patients with LC and 25 healthy controls. Child-Pugh score was used for evaluation of the LC severity. IP was assessed by the rise in levels of iohexol, which was administered orally (25 mL, 350 mg/mL) 2 h after breakfast. Three and six hours later serum (SIC mg/L) and urine (UIC g/mol) iohexol concentrations were determined by a validated HPLC-UV technique. RESULTS: Patients with LC had significantly higher mean SIC value compared with control group at 3 h (2.05 ± 1.67 vs. 1.25 ± 1.41 mg/L, p=0.021, as well as at 6 h (2.20 ± 2.65 vs. 1.11 ± 1.06 mg/L, p=0.001) after ingestion. No significant difference was found in mean SIC value of patients at 3 and 6 h. 23% of the patients had an increased IP. The mean iohexol urine recovery of patients was similar to that of the controls both at 3 h and at 6 h. Mean SIC values were significantly higher in patients with advanced Child C class than in healthy controls or the subgroup with Child B class, both at 3 h (2.54 ± 1.95 mg/L vs. 1.11 ± 1.06 mg/L, p=0.007) or (2.57 ± 1.85 mg/L vs. 1.35±1.32 mg/L, p=0.005) and at 6 h (2.57 ± 1.85 mg/L vs. 1.25 ± 1.40 mg/L, p=0.002) or 2.54 ± 1.95 mg/L vs. 1.07 ± 0.35 mg/L, p=0.02). Cirrhotic patients with ascites had significantly higher SIC in comparison with the controls, both at 3 h (2.31 ± 1.74 vs. 1.25 ± 1.41 mg/, p=0.009) and at 6 h (2.20 ± 1.87 vs. 1.11 ± 1.06 mg/l, p=0.007). In the subgroup of patients with alcoholic LC, the mean SIC values at 3 and 6 h (2.29 ± 1.80, 2.33 ± 1.85 mg/L, respectively) were significantly higher (p= 0.016, p=0.003) compared to the control group (1.25 ± 1.41, 1.11 ± 1.06 mg/L, respectively). CONCLUSIONS: Increased IP is found in 23% of cirrhotic patients. Permeability alterations are significantly more pronounced in patients with advanced LC with the presence of ascites and in those with alcoholic etiology.

Measurement of intestinal permeability using lactulose and mannitol with conventional five hours and shortened two hours urine collection by two different methods: HPAE-PAD and LC-MSMS.

Urinary excretion of two orally-administered non-metabolizable sugars, lactulose and mannitol, is a valuable marker for evaluating intestinal permeability. Usually this test involves a time consuming procedure of about 5 hour's urine collection, which makes the test incompatible to some extent. As the results are expressed as the ratio of lactulose and mannitol recovered in urine within certain time, it may be possible to get similar result despite the reduced urine collection time of 2 hours. Moreover, different laboratories do the test by different methods, which make the results incomparable between laboratories. Here, we are also trying to find the correlation between results from most commonly used methods: HPAE-PAD and LC-MSMS. The lactulose: mannitol (LM) test was performed in a cohort of Bangladeshi infants considered at-risk for environmental enteropathy. 208 urine specimens from 104 (52 male and 52 female) infants were collected at 2 and 5 hours after LM solution administration and were tested for lactulose and mannitol by two different methods, one HPAE-PAD platform and another LC-MSMS platform. Median age of the children was 15.0 months (range 6.9 to 25.8 months) and their mean weight-for-age z-score was -0.92. A higher percentage of lactulose and mannitol recovery was found in 5 hours urine collection than in the corresponding 2 hours by both HPAE-PAD and LC-MSMS method, but when results were expressed as lactulose to mannitol ratio (LMR) there was no significant difference between 2 and 5 hours urine collection in both HPAE-PAD (P = 0.138) and LC-MSMS (P = 0.099) method. LMR based on 2 hours urine collection correlated well with LMR based on traditional 5 hours urine collection (Spearman's correlation coefficient 0.578 and 0.604 respectively for HPAE-PAD and LC-MSMS). In future, LM test to assess intestinal permeability in children can be simplified by shortening the urine collection time from 5 hours to 2 hours.

Measurement of prostaglandin metabolites is useful in diagnosis of small bowel ulcerations.

BACKGROUND: We recently reported on a hereditary enteropathy associated with a gene encoding a prostaglandin transporter and referred to as chronic enteropathy associated with SLCO2A1 gene (CEAS). Crohn's disease (CD) is a major differential diagnosis of CEAS, because these diseases share some clinical features. Therefore, there is a need to develop a convenient screening test to distinguish CEAS from CD. AIM: To examine whether prostaglandin E major urinary metabolites (PGE-MUM) can serve as a biomarker to distinguish CEAS from CD. METHODS: This was a transactional study of 20 patients with CEAS and 98 patients with CD. CEAS was diagnosed by the confirmation of homozygous or compound heterozygous mutation of SLCO2A1. We measured the concentration of PGE-MUM in spot urine by radioimmunoassay, and the concentration was compared between the two groups of patients. We also determined the optimal cut-off value of PGE-MUM to distinguish CEAS from CD by receiver operating characteristic (ROC) curve analysis. RESULTS: Twenty Japanese patients with CEAS and 98 patients with CD were enrolled. PGE-MUM concentration in patients with CEAS was significantly higher than that in patients with CD (median 102.7 vs 27.9 µg/g × Cre, P < 0.0001). One log unit increase in PGE-MUM contributed to 7.3 increase in the likelihood for the diagnosis of CEAS [95% confidence interval (CI) 3.2-16.7]. A logistic regression analysis revealed that the association was significant even after adjusting confounding factors (adjusted odds ratio 29.6, 95%CI 4.7-185.7). ROC curve analysis revealed the optimal PGE-MUM cut-off value for the distinction of CEAS from CD to be 48.9 µg/g × Cre with 95.0% sensitivity and 79.6% specificity. CONCLUSION: PGE-MUM measurement is a convenient, non-invasive and useful test for the distinction of CEAS from CD.

Markers of Intestinal Damage and their Relation to Cytokine Levels in Cardiac Surgery Patients.

OBJECTIVES: In patients undergoing cardiac surgery, both extracorporeal circulation (ECC) and intraoperative mesenterial hypoperfusion may account for increased cytokine levels and lead to postoperative gastrointestinal (GI) symptoms. METHODS: We investigated levels of the intestinal damage markers intestinal fatty acid binding protein (I-FABP in plasma [n = 72] and urine [n = 37]), citrulline (in plasma [n = 35]), and claudin-3 (in urine [n = 37]) in patients undergoing aortic or mitral valve surgery with or without coronary artery bypass grafting. Furthermore, the relationship between these markers and the surgery-induced cytokine response was explored by measuring serial plasma levels of tumor necrosis factor-α, interleukin (IL)-6, IL-8, and IL-10 (n = 35). Finally, the relationship between markers of intestinal damage and GI-symptoms (abdominal pain, ileus, vomiting, diarrhea, time to first defecation) was assessed. RESULTS: Plasma and urinary I-FABP levels, and urinary claudin-3 levels peaked at the end of surgery, while citrulline levels were not influenced by surgery. ECC duration correlated with plasma I-FABP levels (r = 0.31, P = 0.007). Plasma levels of all measured cytokines increased during surgery, with peak levels observed either at the end of surgery or on the first postoperative day. While ECC duration correlated with IL-6 and IL-8 release (r = 0.43, P = 0.01 and r = 0.36, P = 0.04 respectively), there was no direct relationship between I-FABP and claudin-3 levels and cytokine concentrations. No patients developed significant GI or non-GI complications, and I-FABP and claudin-3 release appeared not to be related to postoperative GI symptoms, although the incidence of these symptoms may have limited a reliable assessment. CONCLUSIONS: Longer duration of ECC is associated with a more pronounced release of intestinal injury markers and inflammatory cytokines, but intestinal injury markers are not directly related to the observed increase in cytokine levels or GI-symptoms. These findings indicate that ECC duration contributes to the cytokine response observed in cardiac surgery patients and that intestinal injury itself is not a causative factor for this response.

Arteriolar Hyalinosis Predicts Increase in Albuminuria and GFR Decline in Normo- and Microalbuminuric Japanese Patients With Type 2 Diabetes.

OBJECTIVE: This study investigated the association between renal histology, as assessed by morphometric analysis using light (LM) and electron (EM) microscopy, and changes in urinary albumin excretion (UAE) and glomerular filtration rate (GFR) in Japanese people with type 2 diabetes in the early stages of diabetic nephropathy. RESEARCH DESIGN AND METHODS: We performed percutaneous renal biopsies in 29 patients with type 2 diabetes (22 men, mean ± SD age 49 ± 10 years and GFR 119 ± 27 mL/min/1.73 m2, with 15 normoalbuminuric [UAE <20 µg/min] and 14 microalbuminuric [UAE 20-200 µg/min]) to clarify which histological factors were associated with changes in UAE and GFR during 8.0 ± 3.5 years' follow-up. Glomerular structural changes including mesangial volume fraction [Vv(Mes/glom)] were estimated using EM, whereas the index of arteriolar hyalinosis (IAH) score was assessed by LM. Patients underwent annual measurement of GFR using iohexol injection with simultaneous urine collections for UAE. RESULTS: Vv(Mes/glom) was negatively correlated with baseline and follow-up GFR but not with UAE. The IAH score was positively correlated with UAE and negatively correlated with GFR at follow-up, but it was not correlated with either UAE or GFR at baseline. GFR at follow-up was significantly decreased from baseline in patients with IAH scores ≥2.0 and significantly lower than in patients with IAH scores <2.0. Patients with IAH scores <2.0 showed no significant change in GFR during follow-up. CONCLUSIONS: Arteriolar hyalinosis is an additional histological predictor for albuminuria increase and GFR decline in normo- and microalbuminuric Japanese people with type 2 diabetes.

Renal oxalate excretion following oral oxalate loads in patients with ileal disease and with renal and absorptive hypercalciurias. Effect of calcium and magnesium.

Intestinal absorption of oxalate was assessed indirectly from the increase in renal oxalate excretion following the oral administration of 5 mmol of stable oxalate. When sodium oxalate alone was given without divalent cations to patients in the fasting state, the urinary oxalate increased promptly (within 2 hours). The increase was more prominent and sustained in those with ileal disease (ileal resection or jujunoileal bypass); thus, 35 per cent of the orally administered oxalate eventually appeared in the urine in the group with ileal disease, 8 per cent in the group with stones (renal and absorptive hypercalciurias) and 9 per cent in the control group. This hyperexcretion of oxalate could be largely, but not totally, ameliorated by the concurrent oral administration of divalent cations. Although urinary oxalate decreased significantly following the oral administration of calcium or magnesium, hyperoxaluria persisted in most patients. The results suggested that the hyperabsorption of oxalate in ileal disease cannot be accounted for solely by an increased absorbable oxalate pool associated with calcium-fatty acid complexation. Moreover, although urinary oxalate decreased, urinary calcium increased concurrently when either calcium or magnesium was given. Thus, there was no significant change or increase in the urinary state of saturation with respect to calcium oxalate.

The importance of urinary magnesium values in patients with gut failure.

OBJECTIVE: To determine whether urinary magnesium (Mg) values in patients with gut failure would be more helpful than serum Mg measurements in assessment of Mg deficiency. DESIGN: We compared serum and urinary Mg values in 16 patients with gut failure and 16 age- and sex-matched control subjects. MATERIAL AND METHODS: Sixteen patients with gut failure (nine women and seven men; mean age, 59 years) had serum and 24-hour urinary mg measured before Mg replacement therapy. Short bowel syndrome was present in 75%, and diffuse small bowel disease was present in 25%. RESULTS: The median value for serum Mg was 1.7 mg/dL for patients and 2.0 mg/dL for healthy control subjects (P < 0.001). The median values for urinary Mg were 19 mg and 127 mg per 24-hour specimen in patient and control groups, respectively (P < 0.001). A strong correlation was noted between serum Mg and urinary Mg levels. All patients had low urinary Mg values even though 9 of 16 (56%) had normal serum Mg values. Two patients with normal serum Mg concentrations had urinary Mg values of 20 mg/24 h (25% of normal). Serum, but not urinary, Mg correlated significantly with the length of remaining small bowel (P = 0.03). CONCLUSIONS: Urinary Mg declines before serum Mg and is an earlier and more reliable indicator of evolving Mg deficiency. On the basis of these observations and those showing beneficial effects of parenterally administered Mg supplements on urinary citrate excretion (and, presumably, formation of calcium oxalate stones), replacement of Mg in patients with gut failure should be targeted at normalizing urinary Mg.

Studies of intestinal permeability in inflammatory diseases using polyethylene glycol 400.

It has been proposed that increased bowel permeability might play a role in the pathogenesis of inflammatory disease. Intestinal permeation was investigated by measuring the 6-hour urinary excretion of polyethylene glycol (PEG) 400 in 40 adult volunteer controls and in patients with inflammatory disease. Of the patients, 15 had Crohn's disease; 7, ulcerative colitis; 2, celiac disease; and 7, rheumatoid arthritis. No significant difference in total urinary excretion over a 6-hour period was found between controls and patients with ulcerative colitis. Patients with Crohn's disease, celiac disease, or with rheumatoid arthritis were found to have significantly decreased urinary excretion of PEG 400. The results of this study indicate that there is no identifiable increase in intestinal permeation as measured by PEG 400 excretion during periods of active inflammatory disease.

A sensitive enzymatic assay for the determination of sucrose in serum and urine.

BACKGROUND: Sucrose permeability has been suggested as a simple and non-invasive marker of gastric mucosal damage. We here report on a sensitive enzymatic assay using four sequential enzyme reactions coupled with reduced thio-NADPH. METHODS: Sucrose is phosphorylated by sucrose phosphorylase (EC2.4.1.7). The subsequent reaction in the presence of phosphoglucomutase (EC5.4.2.2) and glucose-1,6-diphosphate forms glucose-6-phosphate. Sucrose of the monad forms the dyad thio-NADPH. The reaction is monitored by changes in absorbance at 405 nm. RESULTS: The lower limit of detection (3SD method) was 2.8 micromol/l for serum and 7.0 micromol/l for urine. The precision of the method was <4.0%, and has sufficient analytical range. CONCLUSIONS: The assay was sensitive enough to monitor serum sucrose concentrations during the sucrose permeability test and an automated assay may be useful in a large number of subjects.

The ursodeoxycholic acid-p-aminobenzoic acid deconjugation test, a new tool for the diagnosis of bacterial overgrowth syndrome.

OBJECTIVE: To determine the possible complementary role of the ursodeoxycholic acid-p-aminobenzoic acid (UDCA-PABA) loading test in the diagnosis of intestinal bacterial overgrowth. DESIGN: A prospective clinical study. PATIENTS AND METHODS: The hydrogen breath and UDCA-PABA tests were performed simultaneously in 68 patients with suspected contaminated small bowel syndrome (CSBS), and in 10 healthy control subjects. The hydrogen breath test was performed by oral loading of 25 g of lactose and/or 10 g of lactulose. The UDCA-PABA test was carried out by oral loading of 250 mg of UDCA-PABA conjugate, followed by measurement of the amount of PABA excreted in the urine. The diagnosis of bacterial overgrowth was considered to be established when either the hydrogen breath test or the UDCA-PABA test produced abnormal results. RESULTS: Thirty-five of the 68 patients proved to have CSBS. In 13 of these 35 patients, only the enhanced urinary PABA excretion (11.7 +/- 1.42 mg vs. 3.6 +/- 0.68 mg) indicated bacterial overgrowth, 15 of the 35 patients gave only a positive hydrogen breath test, and in the remaining seven cases the results of both tests were abnormal. In eight CSBS patients, the urinary excretion of PABA was decreased significantly following 10-day tinidazole treatment (5.5 +/- 1.29 mg vs. 13.1 +/- 2.07 mg). CONCLUSION: The UDCA-PABA test is a valuable clinical method for the detection of bacterial overgrowth, especially in cases where hydrogen production alone fails to reveal CSBS. It is also a useful procedure for evaluating the efficacy of antibacterial treatment.

Modern approach for determination of lactulose, mannitol and sucrose in human urine using HPLC-MS/MS for the studies of intestinal and upper digestive tract permeability.

A new analytical procedure was described for the simultaneous determination of lactulose, mannitol and sucrose in urine, in which HILIC chromatography and tandem mass spectrometry detection are used. Sugars are orally administered for the estimation of intestinal permeability in children digestive tract. Samples were purified by dispersive solid phase extraction (d-SPE) using Amberlite MB150 resin. Raffinose was selected as an internal standard. The chosen chromatographic separation was carried out on ZIC(®)-HILIC column in 10 min at a flow rate of 0.3 mL/min, using mixture of acetonitrile (ACN) and ammonium acetate (NH(4)Ac) in water (H(2)O) as the mobile phase. Within-run precision (CV) measured at three concentrations was 1.08%, 0.32% and 0.49% for lactulose; 1.88%, 0.47% and 0.75% for mannitol, 2.95%, 1.31% and 0.6% for sucrose. Between-run CVs were 0.75%, 1.1% and 1.2% for lactulose; 1.1%, 1.02% and 1.01% for mannitol; 1.17%, 1.4% and 1.05% for sucrose. Analytical recovery of all three sugar probes was 95.06-99.92%. The detection limits were: 15.94 ng/mL for lactulose, 17.10 ng/mL for sucrose and 11.48 ng/mL for mannitol. The proposed method is rapid, simple, sensitive and suitable for the determination of intestinal permeability of the sugar derivatives in children.