IBS patients frequently report that certain foods trigger symptoms, but scientist Dr. Devinder Kumar at St Georges Hospital Medical School claims there are no well established tests to identify food hypersensitivity.
Irritable bowel syndrome is the most common functional disorder of the gastrointestinal tract, characterised by abdominal pain, bloating and irregular bowel function.
The true prevalence of food hypersensitivity is unknown, says Kumar, but it is estimated that about 5 per cent of the general population have some type of food allergy, while experts estimate food hypersensitivity may affect up to 65 per cent of IBS patients.
IBS patients had higher serum IgG4 antibody titers (measure of concentration) to wheat, beef, pork, and lamb but no significant differences in IgG4 titers to potatoes, rice, fish, chicken, yeast, tomato or shrimp, reports Kumar in the July issue of the American Journal of Gastroenterology.
¡°In keeping with the observation in other atopic conditions, this finding suggests the possibility of a similar pathophysiological role for IgG4 antibodies in IBS,¡± conclude the researchers.
Dr. Kumar and colleagues recruited 108 IBS patients, as well as 43 healthy controls. They carried out IgG4 and IgE titers and skin prick testing to 16 common foods including milk, eggs, cheese, wheat, rice, potatoes, chicken, beef, pork, lamb, fish, shrimp, soy beans, yeast, and tomatoes.
According to the UK researchers, IBS patients had significantly higher IgG4 antibody titers to wheat (P¡ü0.001), beef (<0.001), pork (<0.001), lamb (P=0.009), and soy beans (P=0.012) as compared with healthy controls.
These differences, say the scientists, were maintained across all subgroups. While the antibody titers to potatoes, rice, fish, chicken, yeast, tomato and shrimp ¡°were not significantly different¡±.
Earlier this month ingredients firm Quest launched what it claims is the first probiotic scientifically shown to target IBS symptoms.
The probiotic bacteria Lp299v was developed by the Swedish firm Probi, which licensed rights to the strain¡¯s use in supplements to Institut Rosell in 2003.
The French-Canadian company has signed an agreement with Quest for its exclusive use in the UK market. The Quest product will be available in healthfood stores and for professional therapists, using the trademark Quest Lp299v.