Advanced glycation end products as cause of shrimp allergy

Allergy to shrimps is a lifelong and potentially severe disease which affects 1.3 % of the world population. Shrimps are mainly consumed thermally processed. Heating of foods (e.g. frying, baking, roasting, or boiling) induces chemical reactions which lead to the modifications of food proteins. One such process is the Maillard reaction which generates advanced glycation end (AGE) products. Recent research indicates that AGE products may affect the interaction of food proteins with the immune system resulting in chronic inflammation. Our hypothesis is that cooking-induced AGE products increase the allergenic potential of food proteins by modifying their interactions with the immune system and the gut microbiota. In this project, shrimps will be heat-processed using several conventional cooking methods and studied for the content of AGE products. Shrimps with the highest and lowest AGE product contents will be fed to mice to analyze the type and extent of immune response. In addition, fecal samples from these mice will be studied to determine changes in the gut bacterial population possibly associated with allergy development. The interaction of AGE products with human immune cells - isolated from blood samples of allergic individuals - will also be investigated. These cells will be incubated with proteins extracted from heat- processed shrimps and the release of immunomodulatory molecules will be analyzed. Dietary habits can have a long-term impact on health and the gut microbiome. A diet rich in highly processed foods is associated with a higher prevalence of chronic immune diseases such as allergy. This project will generate new knowledge on how heat-modified food proteins affect the gut microbiome and the immune system.

Food allergy to shrimps affects 3% of the world's population and often leads to severe allergic symptoms, including systemic anaphylaxis. However, it is not yet fully understood what causes shrimp allergy. Advanced glycation end (AGE) products formed in food due to thermal processing such as cooking, frying, microwaving etc. are known to have bad health effects. Our aim was to investigate whether such AGE products formed in shrimps upon thermal processing promote the development of allergy to shrimps. In this project, the major allergens were isolated from heat treated or untreated shrimps and analysed for structural or chemical changes. Their immunological properties were investigated on immune cells derived from shrimp-allergic and non-allergic blood donors. This project showed that AGE-modified shrimp allergens have different structural properties than the allergens found in raw (unprocessed) shrimps. These modified shrimp allergens interacted differently with the human immune cells pushing them towards a state which could promote the initiation of allergic disease. Although AGE formation of shrimp allergens is probably not the only reason for causing shrimp allergy, it provides us with a new direction of research to further investigate external and environmental factors that affect the onset of allergy. This project demonstrated how cooking-induced structural changes in dietary proteins may play a role in their immunogenicity and the onset of allergy. Future research should focus on this phenomenon in other major food groups such as nuts, fish, milk, wheat, eggs and soy.