Allergy or intolerance?
The term intolerance includes both, allergy and intolerances not caused by allergies. However, it is important to differentiate exactly, as – although the symptoms are similar - diagnosis and therapy are different.
If the consumption of food leads to health problems, it is important to find out whether the problems are caused by an intolerance or due to an allergic reaction. What is the difference and why is it essential to differentiate between both terms?
Food intolerance
Contrary to an allergic reaction, the immune system is not involved in intolerances. Causes are manifold, symptoms broad-ranging, but so far, the diagnostic possibilities are limited.
At the same time, more and more people suffer from food intolerances, which shows the urgent need for a valid detection procedure.
We focus in our studies on gluten sensitivity and on diseases induced by histamine, as e.g. histamine intolerance. A special focus is on the influence of the gastrointestinal tract on reactions mediated immunologically.
Gluten sensitivity
For many years, cereal products have been one of the main carbohydrate sources in the western nutrition. At the same time, however, the number of people that develop a wheat intolerance or intolerances to related cereal breeds, as barley, rye, or dinkel wheat, is rising increasingly. Breeding selectively the modern cereal breeds as well as a changed preparation of the food are discussed as possible causes for this development. As the description of its symptoms in the journals is getting more detailed, diseases caused by gluten resp. wheat are now detected early.
There are three different forms of cereal intolerance:
• Celiac disease (mediated immunologically)
• Wheat allergy (mediated by IgE and not mediated by IgE)
• Non-celiac gluten sensitivity (NCGS) – so far there are no suitable diagnostic and therapeutic criteria for this intolerance.
Main focus of our scientific work is to examine these cereal intolerances, especially NCGS, and to determine suitable diagnostic and therapeutic options. Besides the influence of different nutritional regimens (FODMAP diet or gluten free diet), we also examine the influence of intestinal bacteria (microbiome) on these intolerances.
Histamine intolerance
It is suspected that an increased histamine concentration in the blood provokes the manifold and in part very pronounced health problems. They may be caused by a reduced concentration of the enzyme diaminooxidase that breaks down histamine. This metabolic disease is subject of controversial discussions as its detection procedure is very difficult and currently not valid.
We could already show as part of a 24-hours-recording of histamine and diaminoxidase that a relevant number of affected persons with suspicion of histamine intolerance indeed showed an decreased concentration of diaminoxidase. Our team now aims at enhancing the detection procedure for histamine intolerance and at integrating it into the clinical diagnostic.
Food allergies
With food allergies, the immune system overreacts on substances that are per se harmless. The number of diseases caused by food allergies has clearly risen within the last years. The activation of the immune system in the gastrointestinal (GI) tract can lead to in part severe food allergies. Usually, it is not possible to detect these allergies associated with the GI-tract by the established blood and skin tests. A method applied locally in the GI-tract would simplify the proof of a food sensitization and enable a more valid diagnosis. Locally used diagnostic methods that have been published are not suited to be used in the clinical routine as the examination time has to be prolonged and they are vulnerable to failures. We aim at establishing a reliable, practical method to prove evidence for a food allergy mediated locally on the intestinal mucosa.