Jørgen Valeur

Indications of 'atopic bowel' in patients with self-reported food hypersensitivity.

Aliment Pharmacol Ther 31, 1112–1122

Effects of varying dietary content of fermentable short-chain carbohydrates on symptoms, fecal microenvironment, and cytokine profiles in patients with irritable bowel syndrome

A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) is increasingly recommended for patients with irritable bowel syndrome (IBS). We aimed to investigate the effects of a blinded low‐FODMAP vs high‐fructo‐oligosaccharides (FOS) diet on symptoms, immune activation, gut microbiota composition, and short‐chain fatty acids (SCFAs).

Antibiotic or bacterial therapy in post-giardiasis irritable bowel syndrome

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

Subjective health complaints and quality of life in patients with irritable bowel syndrome following Giardia lamblia infection: a case control study.

Objective. Irritable bowel syndrome (IBS) is associated with unexplained medical symptoms, and the degree of somatic comorbidity may indicate whether the aetiology of IBS is predominantly psychological or biological in origin. The purpose of this study was to examine the comorbidity and quality of life of patients with IBS following infection with Giardia lamblia. Material and methods. Sixty-seven consecutive patients with persistent abdominal symptoms, initiated by an acute infection with G. lamblia, completed questionnaires for scoring of subjective health complaints (SHC) and quality of life (Short-form Nepean Dyspepsia Index (SF-NDI)). The scores were compared with corresponding scores in persons from the general population (n=70). Results. Compared with controls, each of the two groups of patients, those with present (n=17) and those with cured (n=50) G. lamblia infection, had significantly higher scores (p<0.0001) on SHC. However, subscores on somatic comorbidity (musculoskeletal pain) were low and similar to those in the general population (OR 1.2 (0.51–2.73)). Quality of life was substantially impaired in the patients; sum scores 30.0±8.0 (mean±SD) and 31.7±9.3 in the patient groups and 13.5±6.8 in the general population (p<0.0001). Conclusions. Patients with post-giardiasis IBS suffer very little somatic comorbidity, suggesting that the aetiology of this form of postinfective IBS is predominantly biological in origin and may thus differ from the more common, non-postinfective forms of IBS. The combination of persisting abdominal symptoms and psychological distress might be a perpetuating factor contributing to low quality of life.

Carbohydrate intolerance in patients with self-reported food hypersensitivity: Comparison of lactulose and glucose

Abstract Objective. Malabsorption of low-digestible carbohydrates is physiological, but poorly tolerated in some patients. We investigated symptom anticipation and microbial fermentation as possible mechanisms of carbohydrate intolerance in patients with self-reported food hypersensitivity. Material and methods. In a randomized, double-blind, cross-over study, 27 consecutive patients with unexplained, self-reported food hypersensitivity were given 10 g lactulose and 10 g glucose (placebo). Symptoms and pulmonary excretion of hydrogen and methane were assessed. Short-chain fatty acids (SCFAs), lactate and prostaglandin E2 (PGE2) were analyzed in rectal dialysis fluid, and compared to dialysates from nine healthy volunteers. Results. Post-lactulose symptom scores were correlated with habitual symptom scores (r = 0.6, p = 0.001), significantly higher than post-glucose symptom scores (p = 0.01) and significantly higher in patients than controls (p = 0.0007). Levels of SCFAs, lactate and PGE2 in rectal dialysates were not significantly different after lactulose and glucose, or between patients and controls. Hydrogen excretion was not correlated with symptom scores. Conclusions. The findings suggest that self-reported food hypersensitivity is related to microbial fermentation of malabsorbed carbohydrates and not to symptom anticipation solely. Levels of SCFAs, lactate and PGE2 in rectal dialysates could not explain the fermentation-associated hypersensitivity.

Intestinal B cell‐activating factor: an indicator of non‐IgE‐mediated hypersensitivity reactions to food?

Aliment Pharmacol Ther 2010; 32: 66–73

Fecal Fermentation in Irritable Bowel Syndrome: Influence of Dietary Restriction of Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols

Background/Aims: Dietary restriction of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) may relieve symptoms in patients with irritable bowel syndrome (IBS). We investigated whether this diet alters microbial fermentation, a process that may be involved in IBS symptom generation. Methods: Patients with IBS were included consecutively to participate in a 4-week FODMAP restricted diet. IBS symptoms were evaluated by using the IBS severity scoring system (IBS-SSS). Short-chain fatty acids (SCFAs) were analyzed in fecal samples before and after the dietary intervention, both at baseline and after in vitro fermentation for 24 h. Results: Sixty-three patients completed the study. Following the dietary intervention, IBS-SSS scores improved significantly (p < 0.0001). Total SCFA levels were reduced in fecal samples analyzed both at baseline (p = 0.005) and after in vitro fermentation for 24 h (p = 0.013). Following diet, baseline levels of acetic (p = 0.003) and n-butyric acids (p = 0.009) decreased, whereas 24 h levels of i-butyric (p = 0.003) and i-valeric acids (p = 0.003) increased. Fecal SCFA levels and IBS symptom scores were not correlated. Conclusion: Dietary FODMAP restriction markedly modulated fecal fermentation in patients with IBS. Saccharolytic fermentation decreased, while proteolytic fermentation increased, apparently independent of symptoms.

Abnormal accumulation of intestinal fluid following ingestion of an unabsorbable carbohydrate in patients with irritable bowel syndrome: an MRI study.

Postprandial discomfort following intake of poorly absorbable, but fermentable carbohydrates is a common complaint in patients with irritable bowel syndrome (IBS). We used lactulose as a model substance for this group of symptom triggering carbohydrates, aiming to visualize the intestinal response in IBS patients compared to healthy controls.

Food allergy alters jejunal circular muscle contractility and induces local inflammatory cytokine expression in a mouse model.

BackgroundWe hypothesized that food allergy causes a state of non-specific jejunal dysmotility. This was tested in a mouse model.MethodsBalb/c mice were epicutaneously sensitized with ovalbumin and challenged with 10 intragastric ovalbumin administrations every second day. Smooth muscle contractility of isolated circular jejunal sections was studied in organ bath with increasing concentrations of carbamylcholine chloride (carbachol). Smooth muscle layer thickness and mast cell protease-1 (MMCP-1) positive cell density were assayed histologically. Serum MMCP-1 and immunoglobulins were quantified by ELISA, and mRNA expressions of IFN-γ, IL-4, IL-6 and TGFβ-1 from jejunal and ileal tissue segments were analyzed with quantitative real-time PCR.ResultsOvalbumin-specific serum IgE correlated with jejunal MMCP-1+ cell density. In the allergic mice, higher concentrations of carbachol were required to reach submaximal muscular stimulation, particularly in preparations derived from mice with diarrhoea. Decreased sensitivity to carbachol was associated with increased expression of IL-4 and IL-6 mRNA in jejunum. Smooth muscle layer thickness, as well as mRNA of IFN-γ and TGF-β1 remained unchanged.ConclusionIn this mouse model of food allergy, we demonstrated a decreased response to a muscarinic agonist, and increased levels of proinflammatory IL-6 and Th2-related IL-4, but not Th1-related IFN-γ mRNAs in jejunum. IgE levels in serum correlated with the number of jejunal MMCP-1+ cells, and predicted diarrhoea. Overall, these changes may reflect a protective mechanism of the gut in food allergy.

Do psychological factors predict symptom severity in patients with subjective food hypersensitivity

Abstract Objective. We examined whether psychological factors such as general and gastrointestinal symptom-specific anxiety and depression could predict symptom severity in patients with unexplained, self-reported (subjective) food hypersensitivity. For the purpose, we translated and validated the Visceral Sensitivity Index (VSI). Material and methods. Seventy consecutive patients completed questionnaires for Hospital Anxiety and Depression Scale, VSI, Irritable Bowel Syndrome Symptom Questionnaire, and Subjective Health Complaints Inventory. Relationship between scores on psychological factors and scores on somatic symptoms were studied by multiple regression analyses. Results. Most patients reported non-gastrointestinal symptoms in addition to their irritable bowel syndrome complaints, but general and symptom-specific anxiety, and depression could not explain a significant amount of the variance in somatic complaints. Gastrointestinal symptom-specific anxiety was a significant predictor of gastrointestinal complaints (p = 0.02), and age was the sole significant predictor of non-gastrointestinal complaints (p = 0.01). Approximately 90% of the total variance in symptom severity remained unexplained by the psychological factors. The Norwegian version of the VSI had satisfactory validity (Cronbach alfa = 0.93). Symptom-specific and general anxiety were significantly correlated (r = 0.48, p ≤ 0.0001). Conclusions. Psychological factors were not major predictors of symptom severity in patients with subjective food hypersensitivity. The Norwegian version of VSI had satisfactory validity.