Relation between food provocation and systemic immune activation in patients with food intolerance

Dietary Modifications and Fibromyalgia

Fibromyalgia (FM) is a common rheumatic condition with an unknown etiology. The role of diet in the treatment of FM has been the subject of a small but growing body of research, particularly in Scandinavian nations, with results showing benefits in pain reduction, sleep quality, and general health. Removal of dietary excitotoxins, alteration of cytokines, reduced oxidative stress, improved bowel flora, and central nervous system chemical modification may result from dietary modifications in FM. Based on this review of the literature, it can be concluded that dietary modification may provide relief in a subset of FM patients and certainly warrants further investigation.

Treatment of Crohn's Disease with an IgG4-Guided Exclusion Diet: A Randomized Controlled Trial

BACKGROUND AND AIM

We previously reported an improvement in symptoms in Crohn's disease following an IgG4-guided exclusion diet in an open-label study. We aimed to evaluate, in a double-blinded randomized sham-controlled setting, the efficacy of IgG4-guided diet in improving quality of life in patients with Crohn's disease.

METHODS

Consecutive patients with Crohn's disease and a Crohn's disease activity index (CDAI) of 80-400 attending tertiary and secondary care centers were screened. All patients had IgG4 titers tested against 16 common food types using ELISA. The true diet group excluded four food types with the highest antibody titers for 4 weeks, and the sham group excluded four foods with the lowest antibody titers. Quality of life was assessed using the Short Inflammatory Bowel Disease Questionnaire (SIBDQ) at beginning and end of the trial. Secondary outcome measures were CDAI, Harvey Bradshaw index, serum C-reactive protein, and fecal calprotectin.

RESULTS

One hundred and forty-five subjects were screened and 96 subjects had initial food antibody testing performed with 76 patients completing the study. Milk, beef, pork and egg were the most commonly excluded food types in the true diet group. There was a 3.05 (0.01-6.11) p < 0.05 improvement in SIBDQ and 41 (10.4-71.5) in CDAI p = 0.009.

CONCLUSION

IgG4-guided exclusion diet, as an adjunct, can improve quality of life and symptoms in patients with CD.

Response to intestinal provocation monitored by transabdominal ultrasound in patients with food hypersensitivity

OBJECTIVE

Owing to lack of objective measures, the diagnosis of food hypersensitivity may be difficult. The aim of this study was to investigate whether the intestinal response to direct provocation in patients with food hypersensitivity could be recognized by ultrasound.

MATERIAL AND METHODS

Thirty-two patients with chronic abdominal complaints, self-attributed to food hypersensitivity/allergy were included in the study. Via a nasoduodenal tube, the duodenal mucosa was challenged with the suspected food item dissolved in 10 ml water or saline. Using external ultrasound, the sonographic features (wall thickness and diameter of the duodenal bulb and jejunum, peristalsis activity and luminal fluid) were recorded before and during one hour after challenge.

RESULTS

Sonographic changes were observed after challenge in 14 (44%) of the 32 patients. A positive sonographic response (increased wall thickness, diameter, peristalsis and/or luminal fluid) was significantly related to a positive skin prick test (p = 0.008) and a positive double-blind placebo-controlled food challenge (p = 0.03). A significant correlation was found between provocation-induced symptoms and wall thickness of the duodenal bulb (r = 0.50, p = 0.004) or the jejunum (r = 0.42, p = 0.02). Intra- and interobserver variation of the tracing procedure showed low values.

CONCLUSIONS

Responses of the proximal small intestines to direct provocation (swelling of the wall and exudation of fluid into the lumen) could be visualized by transabdominal ultrasound. This new provocation test could be helpful in the evaluation of patients with food hypersensitivity.

A review of the role of the gut microflora in irritable bowel syndrome and the effects of probiotics

Irritable bowel syndrome (IBS) is a multi-factorial gastrointestinal condition affecting 8-22 % of the population with a higher prevalence in women and accounting for 20-50 % of referrals to gastroenterology clinics. It is characterised by abdominal pain, excessive flatus, variable bowel habit and abdominal bloating for which there is no evidence of detectable organic disease. Suggested aetiologies include gut motility and psychological disorders, psychophysiological phenomena and colonic malfermentation. The faecal microflora in IBS has been shown to be abnormal with higher numbers of facultative organisms and low numbers of lactobacilli and bifidobacteria. Although there is no evidence of food allergy in IBS, food intolerance has been identified and exclusion diets are beneficial to many IBS patients. Food intolerance may be due to abnormal fermentation of food residues in the colon, as a result of disruption of the normal flora. The role of probiotics in IBS has not been clearly defined. Some studies have shown improvements in pain and flatulence in response to probiotic administration, whilst others have shown no symptomatic improvement. It is possible that the future role of probiotics in IBS will lie in prevention, rather than cure.

Food intolerance and allergy in gastrointestinal disorders

Approximately 60 tonnes of food passes through the gastrointestinal tract in an average lifetime. With a surface area second only to the respiratory tract, it is surprising that adverse reactions to food do not occur more frequently.

Immune sensitization to food, yeast and bacteria in Crohn's disease

BACKGROUND

Complex food proteins and enteric flora may act as antigenic stimuli in Crohn's disease. This study assessed the prevalence and magnitude of lymphocyte priming to these antigens in Crohn's disease.

METHODS

A total of 31 Crohn's disease patients (median age 42 years, range 25-72 years) and 22 healthy controls (median 29 years, 23-43 years) were studied. Peripheral blood lymphocytes were collected and incubated with antigens in hanging drop culture for 4 days. The antigens tested were cow's milk, cereals, cabbage group, citrus group, peanut group, Saccharomyces (yeast), Bacteroides, E. coli and Klebsiella. On the 4th day 3H-thymidine incorporation was measured after a 4-h pulse. Responses to antigens were considered positive if mean proliferative values were above the 99% confidence interval for background proliferation.

RESULTS

The mean background and mitogen-stimulated proliferation did not differ between patients and controls. The mean proliferation to antigens was not above background in controls, but in Crohn's patients proliferative responses to all food and bacterial antigens were significantly higher than background values. Twenty-three out of 31 Crohn's patients and five out of 22 controls (P=0.0003) responded to one or more antigens. Sixteen Crohn's patients and two controls responded to four or more antigens (P=0.001, Fisher's exact test).

CONCLUSION

The reactivity of peripheral lymphocytes to food, yeast and bacterial antigens, especially multiple antigens, is common in Crohn's disease. These sensitized lymphocytes may contribute to the inflammatory process.