Fixed Structural Disease May Predict EoE Response to Elimination Diet

Adult patients with eosinophilic esophagitis (EoE) who have fixed structural disease may be less likely to respond to disease-specific diet changes, suggest study findings.

In addition to treatment with proton-pump inhibitors (PPIs) and topical steroids, diet has been linked with controlling inflammation associated with EoE. In the current retrospective study, published in Alimentary Pharmacology & Therapeutics, researchers found that although dietary elimination therapy was effective in patients refractory to PPIs, responses were less likely in patients with EoE characterized by factors associated with fixed structural disease.

The study, say the researchers, adds insight into risk factors predictive of response to dietary intervention, as dietary failure occurs in up to 30% of patients.

“Overall, our findings suggest structural disease may predict dietary nonresponse. Interestingly, fixed stenotic disease has been shown to be a predictor of nonresponse to steroid therapy as well,” explained the group. “While one expects structural disease to predict symptom failure with dietary therapy, it is surprising that it is predictive of histologic failure a well. Two possible explanations why dietary therapy may not be effective in patients with structural disease are: fibrotic disease represents more aggressive disease that is inherently dietary resistant, or that fibrotic disease represents chronic disease that is no longer responsive to dietary therapy.”

The researchers evaluated the responses of 68 patients following the six-food elimination diet (SFED)—a program that excludes dairy, nuts, eggs, soy, wheat, and fish—between 2012 and 2019. Across the group, 62% of patients responded to the SFED or an extended SFED program (ExSFED), which also excludes legumes and corn. Nineteen percent of patients required the ExSFED.

Results from a multivariate analysis showed that only a higher prediet total endoscopic reference score had implications for dietary nonresponse, defined as failure to lower the number of eosinophils per high-power field to below 15 eos/hpf. Having a history of food impaction was found to have no significant association with a failure to respond to the diet.

“This association needs further study and should be taken into consideration when discussing and selecting therapeutic options for the EoE patient. In patients failing the standard US SFED diet, restriction of corn and legumes may further identify dietary responders. Though not our primary aim, we observed a poor correlation between histologic and symptomatic flares consistent with previous findings, emphasizing the importance of confirming histologic response before committing patients to life-long dietary changes.”

Due to the challenges and costs associated with strict dietary elimination diets, a step-up approach is recommended, starting with elimination of dairy and wheat—the most common triggers—followed by a 4-food elimination diet before working up to SFED if patients are refractory.

Among responders to dietary therapy, most flared with 1 (38%) or 2 (23%) foods. In line with previous research, dairy (59%) and wheat (29%) were the most common triggers, although the researchers noted that only 2 (4.8%) responders would have been detected with this 2-food elimination diet.

Reference

Wang L, Mara K, Ravi K, et al. Predictors of histologic response to dietary therapy in eosinophilic oesophagitis. Aliment Pharmacol Ther. Published online September 26, 2022. doi: 10.1111/apt.17221