Few studies have been conducted to optimize safety of multiple food allergen oral immunotherapy (OIT) in conjunction with Omalizumab as well as to identify the immunological mechanism(s) underlying any long-lasting effects of OIT. To address these issues in the field of food allergy research, we have designed this study to test whether: 1) Omalizumab improves the safety of multiple food allergen OIT in subjects with multi food allergies, 2) Omalizumab treatment with multiple food allergen OIT is associated with the ability to use a lower maintenance dose of each food allergens in the OIT regimen, particularly in younger subjects with food allergies.