The Role Of Food Intolerance Mediated By IgG In The Diseases Of Irritable Bowel Syndrome With Diarrhea

Objective: The purpose of this study was to explore the role of food intolerance in the disease of the irritable bowel syndrome with diarrhea(IBS-D)so as to find a simple, effective and economical strategy for treatment of the diseases. Moreover, the aim of the research was to provide theoretical support for the treatment of IBS-D.Methods: 77 ethnic Chinese patients with IBS-D were enrolled in this study as were 26 age-sex-matched controls. The specific IgG antibodies of 14 different food antigens concentrations in serum were screened by enzyme linked immunosorbent assay (ELISA). The main symptoms of the patients were assessed by using a questionnaire scoring system. Patients with IBS-D adjusted their diet according to the assay results. The follow-up visits were lasted for 12 weeks.Results: 1. IBS-D patients showed a high positive rate of serum food-specific IgG antibodies in serum compared with the control group (IBS-D, 50.65%; control, 15.39 %; P<0.01). And the food-specific IgG antibody levels of the two groups had statistically difference (Z =-3.220, P = 0.001).2. The positive rate of 14 kinds of serum food-specific IgG antibodies in IBS-D patients were listed below: egg white/egg yolk (32.47%), tomatoes(14.28%), crab (9.09%), milk(6.49%), soybean (6.49%), mushroom (3.90%), corn (2.60%), rice(1.30%), wheat(1.30%), chicken (1.30%), codfish (1.30%); and pork, beef, shrimp specific IgG were negative. Mild elevation of specific IgG to egg white/egg yolk, milk and tomato in normal controls were detected and the specific IgG to other foods were negative.3. The positive rate of serum food-specific IgG antibodies of egg white / egg yolk were statistically different between the two groups (P<0.05) in 14 kinds foods, but the correlations between the specific IgG antibody levels and scores of the symptoms of IBS-D demonstrated no statistical significance (rs = 0.142, P = 0.218). 4. The therapeutic effect:⑴After eliminating the positive foods for 4 weeks, the total symptom scores of IBS-D decreased from 9.06±2.06 down to 6.40±2.57, the scores dropped to 4.54±2.59 by 8 weeks and 3.60±2.58 by 12 weeks. The scores decreased significantly compared with before treatment (P<0.01).⑵Eliminating the positive foods for 4 weeks, the symptoms of IBS-D patients such as abdominal distension, the shape of stool, the total symptom scores improved compared with those before treatment (P<0.01), after 8 weeks treatment, the symptom and frequency of abdominal pain, the frequency of diarrhea, the severity of abdominal distension, the shape of stool and the total symptom score (P<0.01).⑶After 12 weeks, 65.71% of patients had reliefed, 22.86% had mild reliefed and 11.43% of patients was observed no effect, the total effective rate was 88.57%.Conclusions: 1. The high levels of food intolerance and food-specific IgG antibody levels in IBS-D were found in the study. The results suggest that abnormal IgG-mediated immune response plays an important role in the pathogenesis in IBS-D.2. The positive rate of serum food-specific IgG antibodies of egg white / egg yolk had showed the highest levels in 14 kinds foods, but the severity of IBS-D have no correlation with the IgG antibody levels.3. After eliminating the positive foods according to the test results for 12 weeks, the main symptoms significantly improved in patients with IBS-D. And the therapy is simple,economic and effective .