title: Food-specific IgG4 antibody-guided exclusion diet improves symptoms and rectal compliance in irritable bowel syndrome.
abstract: OBJECTIVE
  Dietary modification improves symptoms in irritable bowel syndrome (IBS). Identification of offending foods by dietary elimination/re-challenge is cumbersome. IgG4 antibodies to common food antigens are elevated in IBS. The aim of this article was to evaluate the effect of exclusion diet based on IgG4 titres on IBS symptoms and rectal sensitivity and compliance.
  
  
  METHODS
  The study comprised 25 patients with IBS (3 M, 22 F, mean age 43 years, Rome II criteria). IgG4 titres to 16 foods (milk, eggs, cheese, wheat, rice, potatoes, chicken, beef, pork, lamb, soya bean, fish, shrimps, yeast, tomatoes and peanuts) were measured. Foods with titres >250 microg/l were excluded for 6 months. Symptom severity was assessed with a previously validated questionnaire at baseline, at 3 months and at 6 months. Rectal compliance and sensitivity were measured in 12 patients at baseline and at 6 months.
  
  
  RESULTS
  IgG4 antibodies to milk, eggs, wheat, beef, pork and lamb were commonly elevated. Significant improvement was reported in pain severity (p < 0.001), pain frequency (p = 0.034), bloating severity (p = 0.001), satisfaction with bowel habits (p = 0.004) and effect of IBS on life in general (p = 0.008) at 3 months. Symptom improvement was maintained at 6 months. Rectal compliance was significantly increased (p = 0.011) at 6 months but the thresholds for urge to defecate/discomfort were unchanged.
  
  
  CONCLUSIONS
  Food-specific IgG4 antibody-guided exclusion diet improves symptoms in IBS and is associated with an improvement in rectal compliance.
authors.affiliation: OGEM Department, St George's Hospital Medical School, London, UK.
authors.forename: Sameer
authors.initials: S
authors.lastname: Zar
authors.forename: Lynne
authors.initials: L
authors.lastname: Mincher
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Benson
authors.forename: Devinder
authors.initials: D
authors.lastname: Kumar
mesh_terms: D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D003967:Diarrhea / Q000517:prevention & control; D004032:Diet; D005260:Female; D005502:Food; D005512:Food Hypersensitivity / Q000276:immunology / Q000517:prevention & control; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D043183:Irritable Bowel Syndrome / Q000175:diagnosis / Q000178:diet therapy* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D017288:Pain Threshold / Q000502:physiology; D017060:Patient Satisfaction; D011788:Quality of Life; D012007:Rectum / Q000502:physiology*; D018570:Risk Assessment; D012684:Sensory Thresholds / Q000502:physiology; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D000888:Antibodies, Anti-Idiotypic; D007074:Immunoglobulin G