**4.4 Role of dietary interventions in eosinophilic esophagitis**

In most cases, but not all, EoE is triggered by food antigens. Hence, the nutrition plays an important part in both the pathogenesis and the treatment of the disease [117]. In pediatric and adult populations, food antigens are clearly antigenic triggers for EoE induction and exacerbation [118]. In 1995, Kelly and Sampson proposed that acid persistent esophageal eosinophilia can be caused by food antigen exposure in children [117]. Ever since the direction toward studying the role of food allergens in the pathogenesis and the treatment of EoE has been established. Some of the therapies that have proven the efficacy are the empiric elimination diets, such as the famous 6 food elimination diets (6-FED). These six foods are wheat, milk, egg, nuts, soy, fish, and eggs [119]. In animal studies, it was shown that accumulation of eosinophils in the murine esophagus occurred after the introduction of peanuts and eggs [120, 121]. Statistics show that 77% of patients with EoE have at least one positive skin-prick test (SPT) for at least 1 food allergy and up to 50% of adults have at least 1 positive test for food allergy [122, 123].

Currently, there are diets approaches that are used for EoE patients: 1) A crystalline amino acid-based elemental diet (ELED), 2) 6-FED, 3) 4-FED, 4) 2-FED) 5) Cow's milk elimination diet [124–126]. The amino acid diet is useful as it can eliminate all possible allergens and it has shown improvement in the symptoms in many cases, and the diet can last for 6 weeks. Initially, the 6-FED was studied in pediatric patients from Chicago in 2006, in which six food groups responsible for most IgEmediated food reactions were eliminated for 6 weeks [127]. All studies have consistently shown that nuts and fish/seafood rarely trigger EoE in response to a 6FED, but cow's milk is by far the most common cause of EoE, followed by wheat/gluten, egg, and, to a lesser extent, wheat/gluten [118, 127–132]. The 4-FED is based on the elimination of the most common food triggers in EoE (animal milk, gluten-containing cereals, eggs, and legumes). Cow's milk (85%), egg (35%), wheat (33%), and soy (19%) were the most common food triggers. The 2-FED is based on the elimination of milk and gluten [126]. After reintroduction of individual foods, cow's milk was found to be the only trigger food in 55% of pediatric responders [133]. Therefore, the 1-FED or the cow's milk elimination diet could be recommended for some patients. One of the clinical practices in the dietary therapy is that a clinician could start with a 1-FED diet, if no response is observed the clinician could upgrade to 2-FED, 4-FED, or 6-FED. Patients could have more than food allergens; therefore, 6-FED is considered the most efficient diet (**Figure 1**) [125].

*Autoimmune Diseases of the GI Tract Part II: Emergence of Diagnostic Tools and Treatments DOI: http://dx.doi.org/10.5772/intechopen.106185*

**Figure 1.** *The various types of food elimination diets.*
