Primary: Nutritional therapy in the form of a whole-food based smoothie can be used to induce remission of active Crohn's disease.

Secondary: Consuming a whole foods based smoothie will result in measurable changes to the microbiome of individuals with Crohn's disease and healthy controls.

The specific aims of this proposal are:

1. To develop a whole-food based smoothie, based on principles of the specific carbohydrate diet, that is comparable in macronutrients and micronutrients to formulas used for exclusive enteral nutritional (EEN) therapy in Crohn's disease.
2. To evaluate the ability of a whole-food based smoothie to induce remission of active Crohn's disease.
3. To evaluate changes to the intestinal microbiome in healthy individuals consuming a whole-food based smoothie diet.

This will be an open label, pilot study over 4 weeks in children with newly diagnosed Crohn's disease treated with a smoothie designed to emulate formulas used for exclusive enteral nutritional therapy. In place of formula, whole-foods based smoothie recipes and the food to create the smoothies will be given to each participant/family. The smoothies will be based upon the concept of reverse-engineering of exclusive enteral nutrition (RE-EEN). The smoothie recipes will involve whole foods that can be blenderized to liquid consistency. Similar to the formulas used for EEN, the smoothies will provide calories, protein, fat, and carbohydrates in a distribution to support growth and development.

Inclusion Criteria:

1. Age 8 -21 years old
2. Diagnosis of Crohn's disease within 4 weeks of study entry
3. Active Crohn's disease, as defined by Pediatric Crohn's Disease Activity Index (PCDAI) ≥10.
4. Participant capable of giving informed consent, or if a minor the parent/guardian is capable of giving informed consent

Exclusion Criteria:

1. History of surgery for Crohn's disease
2. Perianal disease as part of Crohn's disease phenotype
3. Prior treatment with EEN or the specific carbohydrate for Crohn's disease
4. Prior treatment with any immunosuppressive medication (corticosteroids, anti-TNF-alpha agent, azathioprine, methotrexate, etc.)
5. Prior treatment with antibiotics for Crohn's disease
6. Known allergies to any of the food components in the smoothie
7. Admission to hospital due to severity of Crohn's disease and associated symptoms
8. Unwillingness to provide informed consent

Not Discussed