The enzyme transglutaminase, which is added to some breads and croissants to make the dough more pliable, may act upon gliadin (a glycoprotein present in glutenous cereals) to generate the epitope associated with the coeliac response and with anaphylaxis to wheat.

A letter by two researchers in New Zealand published in the journal Trends in Food Science & Technology[1] suggests that transglutaminase (TG) should not be added to cereal products containing wheat, barley, rye or oats until safety checks have been carried out.

A researcher from the biochemistry laboratory in the Centre Hospitalier Chubert , Vannes in France later published an article in the journal Allergie et immunologie about the rôle of TG in both coeliac disease and wheat-dependent exercise-induced anaphylaxis (multi-system allergic reaction on exposure to wheat and during subsequent exercise).[2] The latter condition is not necessarily linked to gluten intolerance, but involves an IgE response.

Transglutaminases transform proteins by deamidation and/or transamidation, the latter cross-links proteins together. New epitopes have been suspected in cases of anaphylaxis to wheat isolates (a food ingredient consisting mainly of deamidated gluten proteins). As a microbial TG is included in many food technological processes, the author concludes: "its safe use should be checked. This assessment must cover not only the safety of the TG itself but also that of the deamidated/cross-linked proteins generated by this enzyme."

Diagnosis of wheat intolerance using skin prick testing and sensitization against wheat proteins is not very accurate.[3] As a result of this, the number of individuals diagnosed with irritable bowel syndrome (IBS) patients who have "food allergy" may be larger than believed.[4] If the interaction with the lectins in wheat germ agglutinin and blood group antigens is taken into account, a lot of the dietary intolerances to eating grain-based foods can be explained. Additives in factory-made baked goods is another reason to eat organically produced bread, with ingredients according to blood group.

Follow up:

References:

1. Gerrard J A, Sutton K H (2005) "Addition of transglutaminase to cereal products may generate the epitope responsible for coeliac disease". Trends in Food Science and Technology 16 (11): 510-12.

doi: 10.1016/j.tifs.2005.07.002

2. Malandain H (2005). "Transglutaminases: a meeting point for wheat allergy, celiac disease, and food safety". Allerg Immunol (Paris) 37 (10): 397-403. PubMed: 16528904.

3. Palosuo K. (2003) "Update on wheat hypersensitivity." Curr Opin Allergy Clin Immunol 3 (3): 205-9. PubMed 12840704

4. Simonato B, De Lazzari F, Pasini G, et. al. (2001). "IgE binding to soluble and insoluble wheat flour proteins in atopic and non-atopic patients suffering from gastrointestinal symptoms after wheat ingestion." Clin Exp Allergy 31 (11) 1771-8. 11696054

PubMed: 11696054