Food Allergies, Food Intolerances, and Carbohydrate Malabsorption

Abstract

Up to 20% of the general population and more than half of the patients with irritable bowel syndrome report recurrent adverse reactions to specific food(s) or food group(s). Most of these reactions are not driven by the immune system and they are known as food intolerances. These nonimmunological adverse food reactions can result from a variety of disorders, including gastroesophageal reflux disease (GERD), metabolic diseases, toxin-mediated reactions, gastrointestinal infections, deficiency of digestive enzymes, and disorders resulting from many anatomic and neurologic abnormalities. In contrast, food allergy is an abnormal immunological reaction to food. It is broadly categorized into immunoglobulin E (IgE)-mediated, non-IgE-mediated, and mixed IgE/non-IgE-mediated. In this chapter, a case study of wheat-related disorders is presented in order to demonstrate the key differences between food allergy and intolerance and to discuss the approach to their diagnosis and treatment.