Based on their retrospective findings, the researchers suggest the diet is a potentially effective option for these patients who may face challenges with other elimination diets.
A specialized elimination diet may be a potential option for children with non-esophageal eosinophilic gastrointestinal disorders, a group of patients for whom an effective dietary approach is being explored.
The modified 6-food elimination diet, consisting of amino-acid–based and hypoallergenic foods, was tolerated in all patients adhering to the diet through the induction phase, with clinical improvements and no serious safety signals. Based on their retrospective findings, the researchers suggest the diet is a potentially effective option for these patients who may face challenges with other elimination diets.
“Since non-IgE-dependent allergic inflammation caused by food allergens is considered one of the important causes of non-EoE EGIDs, establishing an effective dietary therapy is being pursued,” wrote the researchers. “Dietary therapy is expected to be a radical remedy that will not merely temporarily suppress inflammation but will eliminate the cause of disease. Elemental diets that use an amino-acid-based formula that is free of antigenic proteins, and 6-food elimination diets (SFEDs) that eliminate 6 main food groups from wheat, milk, eggs, meats, nuts, soy, and seafood, were established as treatment options for EoE and have been frequently used in non-EoE EGID case reports and case series.”
Highlighting the potential disadvantages of SFED diets, including being difficult to adhere to for more than several days and some patients not improving on the diet, the researchers explored the Rainbow Elimination Diet, which removed rice and 10 additional foods, and consisted of an amino-acid based formula, potatoes, vegetables, and fruits.
The group reviewed medical records from pediatric patients, aged between 2 and 17 years, following the modified SFED diet their approach between January 2010 and December 2018. Twenty-three patients were initially enrolled in the study, 4 of which improved on other treatments, 6 improved with the elimination of 1-3 foods, and 6 improved with the elimination of 6-7 foods, resulting in 7 patients who were followed for the intervention.
There were 6 patients who followed the diet for the first 14 days—the induction phase—and there were 5 patients who exhibited symptoms prior to starting the diet, all of which were symptom free after the 14-day period.
While the diet was insufficient in fat and selenium, no patients showed signs of malnutrition. Five of the 7 patients lost weight—with a median weight change of –0.6 kg (range –1.3 to 1.9 kg)—likely due to an increase in serum protein, resulting in reduced edema, explained the researchers. The researchers noted that the weight of these 5 patients recovered throughout long-term observation.
All 4 patients with hypoproteinemia showed improvements in serum albumin. According to the researchers, this finding suggests a reduction in the intestinal mucosal inflammation, a halting of protein leakage from the stomach and intestine, and improvement in the absorption of nutrients from the small intestine. Laboratory data also showed a reduction in the absolute eosinophil count in 6 patients.
“Our next paper will describe the results of the reintroduction phase of the Rainbow ED. We need to develop restriction diets that taste better. Sweets and snacks are important pleasures, especially for children, and they should be made using safe ingredients,” wrote the researchers. “A randomized controlled trial should be conducted to compare SFED and the Rainbow ED so that the effects of the Rainbow ED can be clarified. Nationwide, long-term food challenge tests need to be conducted to more thoroughly identify the causative foods so that we can further refine the contents of the Rainbow ED.”
Nagashima S, Yamamoto M, Inuzuka Y, et al. Tolerability and safety of a new elimination diet for pediatric eosinophilic gastritis and duodenitis. Allergol Int. Published online November 19, 2022. doi: 10.1016/j.alit.2022.11.001