Development and Validation of Test for "Leaky Gut" Small Intestinal and Colonic Permeability Using Sugars in Healthy Adults.

BACKGROUND: Oral monosaccharides and disaccharides are used to measure in vivo human gut permeability through urinary excretion. AIMS: The aims were as follows: (1) to obtain normative data on small intestinal and colonic permeability; (2) to assess variance on standard 16 g fiber diet performed twice; (3) to determine whether dietary fiber influences gut permeability measurements; and (4) to present pilot data using 2 selected probes in patients with diarrhea-predominant irritable bowel syndrome (IBS-D). METHODS: Sixty healthy female and male adults, age 18-70 years, participated in 3 randomized studies (2 studies on 16.25 g and 1 study on 32.5 g fiber) in otherwise standardized diets. At each test, the following sugars were ingested: 12C-mannitol, 13C-mannitol, rhamnose (monosaccharides), sucralose, and lactulose (disaccharides). Standardized meals were administered from 24 hours before and during 24 hours post-sugars with 3 urine collections: 0-2, 2-8, and 8-24 hours. Sugars were measured using high-performance liquid chromatography-tandem mass spectrometry. Eighteen patients with IBS-D underwent 24-hour excretion studies after oral 13C-mannitol and lactulose. RESULTS: Baseline sugars (>3-fold above lower limits of quantitation) were identified in the 3 studies: 12C-mannitol in all participants; sucralose in 4-8, and rhamnose in 1-3. Median excretions/24 h (percentage of administered dose) for 13C-mannitol, rhamnose, lactulose, and sucralose were ∼30%, ∼15%, 0.32%, and 2.3%, respectively. 13C-mannitol and rhamnose reflected mainly small intestinal permeability. Intraindividual saccharide excretions were consistent, with minor differences with 16.25 g vs 32.5 g fiber diets. Median interindividual coefficient of variation was 76.5% (10-90 percentile: 34.6-111.0). There were no significant effects of sex, age, or body mass index on permeability measurements in health. 13C-mannitol measurements are feasible in IBS-D. CONCLUSIONS: Baseline 12C-mannitol excretion precludes its use; 13C-mannitol is the preferred probe for small intestinal permeability.

Differences in Fecal Microbiomes and Metabolomes of People With vs Without Irritable Bowel Syndrome and Bile Acid Malabsorption.

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) is a heterogeneous disorder, but diagnoses and determination of subtypes are made based on symptoms. We profiled the fecal microbiomes of patients with and without IBS to identify biomarkers of this disorder. METHODS: We collected fecal and urine samples from 80 patients with IBS (Rome IV criteria; 16-70 years old) and 65 matched individuals without IBS (control individuals), along with anthropometric, medical, and dietary information. Shotgun and 16S ribosomal RNA amplicon sequencing were performed on feces, whereas urine and fecal metabolites were analyzed by gas chromatography and liquid chromatography-mass spectrometry. Co-occurrence networks were generated based on significant Spearman correlations between data. Bile acid malabsorption (BAM) was identified in patients with diarrhea by retention of radiolabeled selenium-75 homocholic acid taurine. RESULTS: Patients with IBS had significant differences in network connections between diet and fecal microbiomes compared with control individuals; these were accompanied by differences in fecal metabolomes. We did not find significant differences in fecal microbiota composition among patients with different IBS symptom subtypes. Fecal metabolome profiles could discriminate patients with IBS from control individuals. Urine metabolomes also differed significantly between patients with IBS and control individuals, but most discriminatory metabolites were related to diet or medications. Fecal metabolomes, but not microbiomes, could distinguish patients with IBS with vs those without BAM. CONCLUSIONS: Despite the heterogeneity of IBS, patients have significant differences in urine and fecal metabolomes and fecal microbiome vs control individuals, independent of symptom-based subtypes of IBS. Fecal metabolome analysis can be used to distinguish patients with IBS with vs those without BAM. These findings might be used for developing microbe-based treatments for these disorders.

Metabolomics reveals elevated urinary excretion of collagen degradation and epithelial cell turnover products in irritable bowel syndrome patients.

INTRODUCTION: Irritable bowel syndrome (IBS), the most commonly diagnosed functional gastrointestinal (GI) disorder in developed countries, is characterized by chronic abdominal pain, and altered bowel habits. OBJECTIVES: Accurate and timely diagnosis is challenging as it relies on symptoms and an evolving set of exclusion criteria to distinguish it from other related GI disorders reflecting a complex etiology that remains poorly understood. Herein, nontargeted metabolite profiling of repeat urine specimens collected from a cohort of IBS patients (n = 42) was compared to healthy controls (n = 20) to gain insights into the underlying pathophysiology. METHODS: An integrated data workflow for characterization of the urine metabolome with stringent quality control was developed to authenticate reliably measured (CV < 30%) and frequently detected (> 75%) metabolites using multisegment injection-capillary electrophoresis-mass spectrometry. Complementary statistical methods were then used to rank differentially excreted urinary metabolites after normalization to osmolality that were subsequently identified by high resolution tandem mass spectrometry and their electrophoretic migration behavior. RESULTS: Our work revealed ten consistently elevated urinary metabolites in repeat samples collected from IBS patients at two different time points (q < 0.05 after age and Benjamini-Hochberg/FDR adjustment), which were associated with greater collagen degradation and intestinal mucosal turn-over processes likely due to low-grade inflammation. IBS-specific metabolites identified in urine included a series of hydroxylysine metabolites (O-glycosylgalactosyl-hydroxylysine, O-galactosyl-hydroxylysine, lysine), mannopyranosy-L-tryptophan, imidazole propionate, glutamine, serine, ornithine, dimethylglycine and dimethylguanosine. A major limitation in this retrospective case-control study was significant co-morbidity of IBS patients with other illnesses, including depression and prescribed medications as compared to healthy controls. CONCLUSION: This work provides new mechanistic insights into the pathophysiology of IBS while also offering a convenient way to monitor patient disease progression and treatment responses to therapy based on a panel of urinary metabolites that avoids invasive blood sampling, colonoscopy and/or tissue biopsies.

Gastrointestinal Symptoms and Altered Intestinal Permeability Induced by Combat Training Are Associated with Distinct Metabotypic Changes.

Physical and psychological stress have been shown to modulate multiple aspects of gastrointestinal (GI) physiology, but its molecular basis remains elusive. We therefore characterized the stress-induced metabolic phenotype (metabotype) in soldiers during high-intensity combat training and correlated the metabotype with changes in GI symptoms and permeability. In a prospective, longitudinal study, urinary metabotyping was conducted on 38 male healthy soldiers during combat training and a rest period using gas chromatography-mass spectrometry. The urinary metabotype during combat training was clearly distinct from the rest period (partial least-squares discriminant analysis (PLSDA) Q(2) = 0.581), confirming the presence of a unique stress-induced metabotype. Differential metabolites related to combat stress were further uncovered, including elevated pyroglutamate and fructose, and reduced gut microbial metabolites, namely, hippurate and m-hydroxyphenylacetate (p < 0.05). The extent of pyroglutamate upregulation exhibited a positive correlation with an increase in IBS-SSS in soldiers during combat training (r = 0.5, p < 0.05). Additionally, the rise in fructose levels was positively correlated with an increase in intestinal permeability (r = 0.6, p < 0.005). In summary, protracted and mixed psychological and physical combat-training stress yielded unique metabolic changes that corresponded with the incidence and severity of GI symptoms and alteration in intestinal permeability. Our study provided novel molecular insights into stress-induced GI perturbations, which could be exploited for future biomarker research or development of therapeutic strategies.

Urinary proteome analysis of irritable bowel syndrome (IBS) symptom subgroups.

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder characterized by chronic abdominal pain associated with alterations in bowel function. Given the heterogeneity of the symptoms, multiple pathophysiologic factors are suspected to play a role. We classified women with IBS into four subgroups based on distinct symptom profiles. In-depth shotgun proteomic analysis was carried out to profile the urinary proteomes to identify possible proteins associated with these subgroups. First void urine samples with urine creatinine level≥100 mg/dL were used after excluding samples that tested positive for blood. Urine from 10 subjects representing each symptom subgroup was pooled for proteomic analysis. The urine proteome was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using a data-independent method known as Precursor Acquisition Independent From Ion Count (PAcIFIC) that allowed extended detectable dynamic range. Differences in protein quantities were determined by peptide spectral counting followed by validation of select proteins with ELISA or a targeted single reaction monitoring (LC-SRM/MS) approach. Four IBS symptom subgroups were selected: (1) Constipation, (2) Diarrhea+Low Pain, (3) Diarrhea+High Pain, and (4) High Pain+High Psychological Distress. A fifth group consisted of Healthy Control subjects. From comparisons of quantitative spectral counting data among the symptom subgroups and controls, a total of 18 proteins that showed quantitative differences in relative abundance and possible physiological relevance to IBS were selected for further investigation. Three of the 18 proteins were chosen for validation by either ELISA or SRM. An elevated expression of gelsolin (GSN) was associated with the high pain groups. Trefoil Factor 3 (TFF3) levels were higher in IBS groups compared to controls. In this study, the IBS patients subclassified by predominant symptoms showed differences in urine proteome levels. Proteins showing distinctive changes are involved in homeostasis of intestinal function and inflammatory response. These findings warrant future studies with larger, independent cohorts to enable more extensive assessment and validation of urinary protein markers as a diagnostic tool in adults with IBS.

Urine sugars for in vivo gut permeability: validation and comparisons in irritable bowel syndrome-diarrhea and controls.

Mucosal barrier dysfunction contributes to gastrointestinal diseases. Our aims were to validate urine sugar excretion as an in vivo test of small bowel (SB) and colonic permeability and to compare permeability in patients with irritable bowel syndrome-diarrhea (IBS-D) to positive and negative controls. Oral lactulose (L) and mannitol (M) were administered with (99m)Tc-oral solution, (111)In-oral delayed-release capsule, or directly into the ascending colon (only in healthy controls). We compared L and M excretion in urine collections at specific times in 12 patients with IBS-D, 12 healthy controls, and 10 patients with inactive or treated ulcerative or microscopic colitis (UC/MC). Sugars were measured by high-performance liquid chromatography-tandem mass spectrometry. Primary endpoints were cumulative 0-2-h, 2-8-h, and 8-24-h urinary sugars. Radioisotopes in the colon at 2 h and 8 h were measured by scintigraphy. Kruskal-Wallis and Wilcoxon tests were used to assess the overall and pairwise associations, respectively, between group and urinary sugars. The liquid in the colon at 2 h and 8 h was as follows: health, 62 ± 9% and 89 ± 3%; IBS-D, 56 ± 11% and 90 ± 3%; and UC/MC, 35 ± 8% and 78 ± 6%, respectively. Liquid formulation was associated with higher M excretion compared with capsule formulation at 0-2 h (health P = 0.049; IBS-D P < 0.001) but not during 8-24 h. UC/MC was associated with increased urine L and M excretion compared with health (but not to IBS-D) at 8-24 h, not at 0-2 h. There were significant differences between IBS-D and health in urine M excretion at 0-2 h and 2-8 h and L excretion at 8-24 h. Urine sugars at 0-2 h and 8-24 h reflect SB and colonic permeability, respectively. IBS-D is associated with increased SB and colonic mucosal permeability.

Assessment of intestinal permeability using sugar probes: influence of urinary volume.

BACKGROUND: As the accuracy of the "Sugar Test" is currently debated, this study was conducted to focus on how urine volumes may impact the test results. METHODS: Fifty-five subjects, 23 healthy and 32 with Irritable Bowel Syndrome (IBS), were enrolled. Lactulose and D-mannitol dissolved in water were administered to all the participating subjects; the urine excreted was collected and the total urine volume was measured. The urine samples were analyzed by High Performance Liquid Chromatography (HPLC). The results were expressed as percentage of urine recovery of lactulose and D-mannitol and lactulose/D-mannitol ratio (LMR). RESULTS: All subjects were divided into two groups: subjects with urine volume < 500 mL and subjects with urine volume > or = 500 mL. Urine analysis showed that the mean LMR was significantly lower in subjects with urine volume > or = 500 mL than in subjects with urine volume < 500 mL (0.02 +/- 0.02 vs 0.04 +/- 0.04; p < 0.05). A significant increase in D-mannitol recovery was found to be associated with greater urine volumes (p < 0.001). CONCLUSIONS: The urine volume may influence urinary excretion of sugar probes. Intake of liquids should therefore be carefully monitored before and during the test and the volume of urine produced over the period of collection should be precisely measured.

Changes in serum and urinary metabolomic profile after a dietary intervention in patients with irritable bowel syndrome.

BACKGROUND: Irritable bowel syndrome (IBS) is a multi-faceted gastrointestinal disorder where food intake often triggers symptoms. Metabolomics may provide mechanistical insights to why responses to dietary modifications are diverse. OBJECTIVE: This study aimed to identify metabolite patterns related to dietary intake in patients with IBS, and to identify metabolites driving the separation between responders and non-responders to treatment. METHODS: Participants were randomized to a low fermentable oligo-, di-, monosaccharide and polyol (FODMAP) diet (LFD) or traditional IBS diet (TID) for four weeks. Fasting serum and urine samples pre- and post-intervention were analyzed using 1H nuclear magnetic resonance (NMR) metabolomics. Response to treatment was defined as a reduction in IBS severity scoring system (IBS-SSS) ≥50. RESULTS: Twenty-five individuals in the LFD (13 responders) and 28 in the TID (14 responders) were included in these post hoc analyses. In endpoint samples, significant decreases in polyols and glucose were seen in the LFD. Post-intervention samples revealed that LFD responders had significantly increased levels of 2-hydroxybuturate and decreased levels of glucose and pantothenic acid compared to non-responders. For the TID, only weak multivariate models were identified and a larger diversity in metabolite response compared to the LFD were noted. CONCLUSIONS: In this study, metabolite patterns between individuals who responded well to an LFD compared to non-responders could be distinguished. This provides new hypotheses for mechanistic actions related to response to dietary modifications, but the results need to be validated in larger cohorts. CLINICAL TRIAL REGISTRATION: This trial was registered at www.clinicaltrials.gov, registry number NCT02107625.

Effect of Tong Xie Yao Fang on endogenous metabolites in urine of irritable bowel syndrome model rats.

BACKGROUND: Tong Xie Yao Fang is a representative traditional Chinese prescription for the treatment of liver and spleen deficiency, abdominal pain and diarrhea. It has a unique function in the treatment of gastrointestinal dysfunction including irritable bowel syndrome (IBS), is a common functional bowel disease. Its main symptoms are recurrent abdominal pain, diarrhea, constipation or alternations between diarrhea and constipation. There are obvious differences in metabolites between TCM syndromes. By comparing the body fluid metabolism maps of model animals, metabolomics can discover disease biomarkers, analyze the differences in metabolic pathways and understand the pathological process and the metabolic pathways of substances in the body. Thus, the evaluation of animal models tends to be comprehensive and objective. This may provide further understanding between the interaction between Tong Xie Yao Fang and the IBS model. AIM: To evaluate the effect of Tong Xie Yao Fang on IBS rats by using metabolomics method. METHODS: Wistar rats were used to establish IBS models, and then randomly divided into four groups: A model control group and three Tong Xie Yao Fang treatment groups (high, medium and low doses). A normal, non-IBS group was established. The rats were treated for 2 wk. On days 0 and 14 of the experimental model, urine was collected for 12 h and was analyzed by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry. Nine potential biomarkers were identified, and six major metabolic pathways were found to be related to IBS. RESULTS: In the study of metabonomics, nine potential biomarkers including L-serine, 4-methylgallic acid, L-threonine, succinylacetone, prolyl-hydroxyproline, valyl-serine, acetyl citrate, marmesin rutinoside and 5-hydroxy-L-tryptophan were identified in urine, which were assigned to amino acids, organic acids, succinyl and glycosides. Furthermore, the metabolic pathway of L-serine, L-threonine and 5-hydroxy-L-tryptophan was found in the Kyoto Encyclopedia of Genes and Genomes, which mainly involved the metabolism of cysteine and methionine, vitamin B6 metabolism, serotonin synapse, tryptophan metabolism, sphingolipid metabolism, digestion, absorption of protein and amino acid metabolism. These pathways are related to intestinal dysfunction, inflammatory syndrome, nervous system dysfunction and other diseases. CONCLUSION: Tong Xie Yao Fang has pharmacological effects on IBS, and its mechanism may be related to the metabolism of the nine potential biomarkers identified above in urine.

[Serum serotonin concentration and urine 5-hydroxyindole acetic acid excretion in patients with irritable bowel syndrome]. / Steizenie serotoniny w surowicy krwi i wydalanie kwasu 5-hydroksyindolooctowego z moczem u osób z zespolem jelita nadwraziliwego.

UNLABELLED: Serotonin (5-HT) is among other factors involved in gastrointestinal motility, secretion and visceral sensation. Available data suggest that secretion and metabolism of 5-HT may be disturbed in irritable bowel syndrome (IBS). Interpretation of these observations have been hampered by the variable methodology used and small numbers of patients involved in the previous studies. Aim of this study was to measure serum 5-TH concentration under fasting condition in patients with irritable bowel syndrome (IBS), compared with controls (K). The metabolite of serotonine--5-hydroxyindole acetic acid (5-HIAA) in urine was also assessed. METHODS: 71 subjects, aged 19-50 years were included in this study. Three groups were distinguished: group I (n=25)--healthy volunteers, group II (n=23)--patients with constipation predominant (IBS-C), group Ill (n=23)--subjects with diarrhea predominant irritable bowel syndrome (IBS-D). IBS was diagnosed according to Rome Ill Criteria. On the day of the experiment, patients received a standard meal (Nutridrink 6 x 300 kcal) and blood samples were collected during fasting. 5-HIAA concentration was determined in 24-hour urine collection. Concentration of 5-HT and 5-HIAA was measured by immunoenzyme ELISA method employing standard kits IBL nr RE59121 i RE59131 and Labsystems Multiscan detector. RESULTS: The average serotonin concentration during fasting was found in group I--156.67 +/- 49.12 ng/ml, in group II--221.73 +/- 91.56 ng/ml (p < 0.05), in group III--3.50 +/- 1.71 mg/24h. 5- HIAA concentration in urine was decreased in group Ill--3.50 +/- 1.71 mg/24 hrs (p < 0.05) and group II--4.37 +/- 2.95 mg/24 hrs compared with healthy volunteers--5.65 +/- 2.31 mg/24 hrs. CONCLUSION: (1) Serotonin concentration is increased in C-IBS and D-IBS patients. (2) Urine 5-hydroxyindole acetic acid excretion is decreased in IBS-subjects. (3) Disturbed metabolism of serotonin probably may play role in pathogenesis of functional bowel diseases.

Validation of an LC-MS/MS Method for Urinary Lactulose and Mannitol Quantification: Results in Patients with Irritable Bowel Syndrome.

Aim. Lactulose/mannitol ratio is used to assess intestinal barrier function. Aim of this work was to develop a robust and rapid method for the analysis of lactulose and mannitol in urine by liquid chromatography coupled to tandem mass spectrometry. Lactulose/mannitol ratio has been measured in pediatric patients suffering from irritable bowel syndrome. Methods. Calibration curves and raffinose, used as internal standard, were prepared in water : acetonitrile 20 : 80. Fifty µL of urine sample was added to 450 µL of internal standard solution. The chromatographic separation was performed using a Luna NH2 column operating at a flow rate of 200 µL/min and eluted with a linear gradient from 20% to 80% water in acetonitrile. Total run time is 9 minutes. The mass spectrometry operates in electrospray negative mode. Method was fully validated according to European Medicine Agency guidelines. Results and Conclusions. Linearity ranged from 10 to 1000 mg/L for mannitol and 2.5 to 1000 mg/L for lactulose. Imprecision in intra- and interassay was lower than 15% for both analytes. Accuracy was higher than 85%. Lactulose/mannitol ratio in pediatric patients is significantly higher than that measured in controls. The presented method, rapid and sensitive, is suitable in a clinical laboratory.

Renal tubular proteinuria in patients with irritable bowel syndrome.

OBJECTIVE: Irritable bowel syndrome (IBS) is a common condition that is poorly understood. We have previously demonstrated tubular protinuria in patients with inflammatory bowel disease. This study examined whether tubular proteinuria was a feature of IBS. METHODS: Eighty control subjects (male:female, 28:52; age range 20-65 years) and 21 patients with IBS (male:female, 9:12; age range 16-64 years) (not significant) were recruited. Patients with known renal disease, hypertension, diabetes or microbiological evidence of urinary infection were excluded. The IBS patients all fulfilled the ROME II criteria. None had preceding gastroenteritis. Urinary alpha1-microglobulin (alpha1-M) was measured in a second-voided morning urine sample and corrected for urinary concentration by measurement of creatine. Blood samples were analysed for haematochemical indices including C-reactive protein. Statistical analysis was by unpaired t test. RESULTS: None of the IBS patients were reclassified with inflammatory bowel disease over a 5-year follow up period. All had normal haematochemical parameters. Mean +/- standard deviation urinary alpha1-M concentrations were significantly higher in IBS patients than controls (IBS patients, 1.17 +/- 0.65 mg/mmol; controls, 0.75 +/- 0.36 mg/mmol; P < 0.01) and exceeded 1.5 mg/mmol (the upper reference limit) in seven patients. There was no difference in urinary alpha1-M concentrations in the diarrhoea-predominant and constipation-predominant groups (mean +/- standard deviation, 1.342 +/- 0.65 versus 0.76 +/- 0.48 mg/mmol; P = 0.062). CONCLUSIONS: Urinary alpha1-M concentration is commonly increased in IBS, suggesting the presence of renal proximal tubular injury.

The urinary 5-hydroxyindole acetic acid and plasma nitric oxide levels in irritable bowel syndrome: a preliminary study.

BACKGROUND AND AIMS: Postprandial increase of 5-hydroxytryptamine (5-HT) has been implicated in irritable bowel syndrome (IBS). There is evidence that nitric oxide (NO) may act as a mediator of 5-HT-evoked secretions in the colon. Our aim is to investigate the role of urinary 5-hydroxyindole acetic acid (5-HIAA) and plasma NO levels (with diarrhoea) in IBS patients. METHODS: Nineteen (with constipation) IBS patients (group 1), 22 IBS patients (group 2) and 18 healthy controls (group 3) were included in the study. The diagnosis of IBS was made according to the Rome I Criteria. The urine was collected for determination of 5-HIAA and venous blood was collected from each subject for the measurement of plasma NO levels. RESULTS: The levels of urinary 5-HIAA mmol/day and plasma NO mmol/l of group 1 (22.4 +/- 2.2 and 29.4 +/- 2 respectively) were significantly higher than group 3 (14.2 +/- 2.3 and 21.3 +/- 2.1 respectively) (p = 0.036 and p = 0.019 respectively). The NO level of group 1 was also significantly higher than group 2 (21.8 +/- 1.9) (p = 0.021). The 5-HIAA level of group 1 was higher than group 2 (15.2 +/- 2.1) and the difference was marginally significant (p = 0.055). There was no difference between group 2 and group 3 with respect to 5-HIAA and NO levels. CONCLUSIONS: The results of this preliminary study lend support to the involvement of 5-HT in some symptomatology of diarrhoea predominant IBS. Furthermore, NO may be one of the effector mediators of the 5-HT-induced symptoms in these patients.

Differentiating coeliac disease from irritable bowel syndrome by urinary volatile organic compound analysis--a pilot study.

Coeliac disease (CD), a T-cell-mediated gluten sensitive enteropathy, affects ∼ 1% of the UK population and can present with wide ranging clinical features, often being mistaken for Irritable Bowel Syndrome (IBS). Heightened clinical awareness and serological screening identifies those with potential coeliac disease; the diagnosis is confirmed with duodenal biopsies, and symptom improvement with a gluten-free diet. Limitations to diagnosis are false negative serology and reluctance to undergo biopsy. The gut microbiome is altered in several gastrointestinal disorders, causing altered gut fermentation patterns recognisable by volatile organic compounds (VOC) analysis in urine, breath and faeces. We aimed to determine if CD alters the urinary VOC pattern, distinguishing it from IBS. 47 patients were recruited, 27 with established CD, on gluten free diets, and 20 with diarrhoea-predominant IBS (D-IBS). Collected urine was stored frozen in 10 ml aliquots. For assay, the specimens were heated to 40 ± 0.1°C and the headspace analysed by Field Asymmetric Ion Mobility Spectrometry (FAIMS). Machine learning algorithms were used for statistical evaluation. Samples were also analysed using Gas chromatography and mass spectroscopy (GC-MS). Sparse logistic regression showed that FAIMS distinguishes VOCs in CD vs D-IBS with ROC curve AUC of 0.91 (0.83-0.99), sensitivity and specificity of 85% respectively. GCMS showed a unique peak at 4'67 found only in CD, not D-IBS, which correlated with the compound 1,3,5,7 cyclooctatetraene. This study suggests that FAIMS offers a novel, non-invasive approach to identify those with possible CD, and distinguishes from D-IBS. It offers the potential for monitoring compliance with a gluten-free diet at home. The presence of cyclooctatetraene in CD specimens will need further validation.

Effect of self-management intervention on cortisol and daily stress levels in irritable bowel syndrome.

Self-management programs that include cognitive behavioral strategies have been shown to improve gastrointestinal (GI) symptoms, psychological distress, and quality of life (QoL) in persons with irritable bowel syndrome (IBS). However, less is known about the physiological impact of such a change. As part of a randomized controlled trial using a comprehensive self-management (CSM) intervention (n = 126) compared to usual care (UC; n = 62), cortisol levels were measured in 4 weekly first morning urine samples at baseline and at 3-, 6-, and 12-month follow-up. In addition, diary (28 days) ratings of stress were recorded at baseline, 3, 6, and 12 months. The omnibus test of all three outcome times showed no differences in urine cortisol levels between the CSM and UC groups (p = .400); however, at 3 months the CSM group had significantly higher cortisol levels than the UC group (p = .012). The CSM group reported lower daily stress levels (p = .046 from the omnibus test of all 3 time points) than the UC group, with the effect getting stronger over time. Despite marked improvements in reported stress and previously reported GI and psychological distress symptoms at later follow-ups, the CSM program did not reduce urine cortisol levels in adults with IBS. These results suggest that the first-void urine cortisol levels are not reflective of self-reported daily stress in this patient population.

Influence of tianeptine on melatonin homeostasis and psychosomatic symptoms in patients with irritable bowel syndrome.

UNLABELLED: Selective serotonin reuptake inhibitors (SSRIs) exert beneficial effect on gastrointestinal tract (GIT), but its mechanism has not been recognized. One of the hypothesis assumes, that fluoxetine increases indirectly melatonin production. For this reason it can be hypothesized, that administration of drugs of opposite effect, for example tianepine (selective serotonin reuptake enhancer (SSRE), can reduce melatonin production resulting in harmful effects as regards GIT. The aim of the study was to confirm or reject this hypothesis. The study included 100 patients, aged 21-58 years, with irritable bowel syndrome (IBS). Basing on the Rome III Criteria patients with constipation-predominant (IBS-C, n=50) and with diarrhoea-predominant (IBS-D, n=50) and 25 health volunteers (control group C) were distinguished. Visual Analog Scale (VAS) and Hamilton Depression Rating Scale (HDRS) were used to determine the severity of somatic and psychic symptoms. The concentration of 6-sultatoxymelatonin (6-HMS) in the urine was measured by ELISA method. In both groups the patients were administrated tianeptine 12.5 mg three times daily or placebo for 8 weeks. After 8 weeks of tianeptine therapy no significant changes were found in urinary 6-HMS excretion both in IBS-C group (9.9±3.2 versus 11.5±3.5 µg/24 h) and in IBS-D group (11.8±3.3 versus 12.2±3.5 µg/24 h). Eight-week tianeptine therapy resulted in significant decrease of somatic and psychic symptoms in both investigated groups. The improvement in the quality of life indices was obtained in 76.5% of IBS-C and in 63.3% of IBS-D patients. CONCLUSIONS: tianeptine does not impair melatonin homeostasis in patients with IB, diminishes IBS symptoms and improves the patients' quality of life.

Searching for the noninvasive biomarker holy grail: are urine proteomics the answer?

Recently, biobehavioral nursing scientists have focused their attention on the search for biomarkers or biological signatures to identify patients at risk for various health problems and poor disease outcomes. In response to the national impetus for biomarker discovery, the measurement of biological fluids and tissues has become increasingly sophisticated. Urine proteomics, in particular, may hold great promise for biobehavioral focused nursing scientists for examination of symptom-and syndrome-related research questions. Urine proteins are easily accessible secreted proteins that provide direct and indirect windows into bodily functions. Advances in proteomics and biomarker discovery provide new opportunities to conduct research studies with banked and fresh urine to benefit diagnosis, prognosis, and evaluation of outcomes in various disease populations. This article provides a review of proteomics and a rationale for utilizing urine proteomics in biobehavioral research. It addresses as well some of the challenges involved in data collection and sample preparation.

Evaluation of urinary 6-hydroxymelatonin sulphate excretion in women at different age with irritable bowel syndrome.

Melatonin (MT) exerts a beneficial action in the treatment of many diseases, among them also in irritable bowel syndrome (IBS). Its secretion decreases with age, particularly, in the postmenopausal period in women. It has not been determined whether these changes can have an impact on the clinical picture of IBS. The study aimed at evaluating the urinary excretion of the main MT metabolite - 6-hydroxymelatonin sulphate (6-HMS) in women at different age with IBS. The investigations were carried out in five groups of 30 women each. Group Ia (the controls) - premenopausal healthy women (20-39 years), group Ib (the controls) - postmenopausal healthy women (46-66 years), group II - women with constipation predominant IBS (IBS-C; 19-42 years), group III - women with diarrhoea predominant IBS (IBS-D; 20-39 years), group IV - women with IBS-C (49-68 years), group V - women with IBS-D (48-69 years). The diagnosis of IBS was based on the Rome III Criteria after excluding other diseases. On the day of the study the patients remained on the same liquid diet (Nutridrink - 3x400 ml) and 1500 ml of still mineral water. 6-HMS concentration in urine was measured by ELISA method applying IBL antibodies (RE-54031, Immunological Laboratories). The results showed that 24-hour urinary 6-HMS excretion in the studied premenopausal women were as follows: group Ia - 15.13+/-5.83 microg/24 h, group II - 28.85+/-12.59 microg/24 h (p<0,01), group III - 26.10+/-11.76 microg/24 h (p<0,01) and in the postmenopausal subjects they were: group Ib - 10.66+/-3.23 microg/24 h, group IV - 13.73+/-5.09 microg/24 h ((p=0,02), group V - 21.39+/-10.88 microg/24 h (p<0,01). In women with IBS-C the obtained results of 24-hour 6-HMS urinary excretion were independent on the intensity of clinical symptoms. On the other hand, in women with IBS-D, both in the group III and V, higher intensity of ailments was accompanied by significantly increased 6-HMS urinary excretion. The results of the study allowed drawing the following conclusions: (1). 24-hour 6-HMS urinary excretion in women with the constipation-predominant (IBS-C) as well as the diarrhoea-predominant IBS (IBS-D) is higher than in healthy persons both in the premenopausal and postmenopausal period. (2). Relatively high 6-HMS urinary excretion in postmenopausal women with IBS-D indicates an adaptive increase in MT secretion from EC in the gut.

Is melatonin involved in the irritable bowel syndrome?

There is a substantial evidence that large quantities of melatonin are produced in gastrointestinal tract, however, is still unclear which is the role of melatonin in digestive system in human physiology and pathophysiology. In the present study we investigated urinary excretion of a main melatonin metabolite, 6-sulphatoxymelatonin, in patients with irritable bowel syndrome (IBS). The investigation was carried out in 67 persons, both sexes, aged 20-45 years old who according to Rome III Criteria were diagnosed as sufferers of constipation (C-IBS, n=21 persons) or diarrhoea (D-IBS, n=24 persons) form of irritable bowel syndrome and as healthy subjects (K, n=22), matched for control. Samples were obtained from the collected diurnal urine. The concentration of 6-sulphatoxymelatonin (6-SMLT) was measured with ELISA method, creatinine (crea) was automatically analyzed with biochemical analyzer and 6-SMLT/crea calculated. There were statistically significant differences between groups: the 6-SMLT/crea level was lower in C-IBS (103.86+/- 82.83 ng/mg) and D-IBS (112.72+/-85.29 ng/mg) groups compared to K group (202.7+/-89.28 ng/mg), respectively, p=0.002, p=0.003. There were no differences between C-IBS and D-IBS groups, however, there were observed differences between men and women with C-IBS. The 6-SMLT/crea. level was higher in women with C-IBS (139.31+/-96.45) compared to men with C-IBS (35.51+/-41.05) (p=0.04). These results suggest that different melatonin secretion and metabolism may be involved in the pathogenesis of irritable bowel syndrome.

Abnormal intestinal permeability in subgroups of diarrhea-predominant irritable bowel syndromes.

OBJECTIVES: Irritable bowel syndrome (IBS) is a heterogeneous condition and defined according to symptoms. Low-grade inflammation has been associated with IBS, particularly that following infection, but whether altered intestinal permeability profiles relate to irritable bowel subtype or onset is uncertain. Our aim was to compare small and large intestinal permeability in various subtypes of IBS to healthy controls. METHODS: Intestinal permeability was measured using 1.8 MBq of 51Cr-EDTA and collecting urine over 24 h; Study 1: patients with diarrhea-predominant postinfectious IBS (N=15), constipation-predominant IBS (N=15), and healthy controls (N=15); Study 2: two groups of diarrhea-predominant IBS (D-IBS), one with a history of onset after acute gastroenteritis (postinfectious) (N=15) and the other without such a history (nonpostinfectious) (N=15) both compared with healthy controls (N=12). RESULTS: Permeability expressed as percentage of total dose excreted in urine (median [inter-quartile range]). Study 1: Proximal small intestinal permeability was increased in postinfectious IBS (0.19 [0.12-0.23]) in contrast to constipated IBS (0.085 [0.043-0.13]) and controls (0.07 [0.035-0.19]) (p=0.02). IBS patients with eczema, asthma, or hayfever had increased proximal small intestinal permeability compared with IBS patients without atopy (p=0.02). Study 2: Small intestinal permeability was greater in nonpostinfectious diarrhea-predominant IBS (0.84 [0.69-1.49]) compared with postinfectious IBS (0.43 [0.29-0.63], p=0.028) or controls (0.27 [0.2-0.39]), p=0.001). CONCLUSIONS: Small intestinal permeability is frequently abnormal in diarrhea-predominant IBS. Those without a history of infectious onset appear to have a more severe defect.