A 10-year-old boy with a history of asthma and food allergies is diagnosed with Eosinophilic Esophagitis (EoE) after an endoscopy for dysphagia revealed ≥ 15 eosinophils/hpf. He is started on a high-dose proton pump inhibitor (PPI), and a follow-up endoscopy shows significant histologic improvement. What is the most likely mechanism explaining his response to PPI therapy?