The goal of the study is to test the efficacy of a dietary intervention in inducing clinical response and remission for patients with Crohn's disease in a randomized controlled trial. The intervention diet: DAIN has been adapted from the Inflammatory Bowel Disease Anti-Inflammatory Diet or IBD-AID™ taking into account the food availability and preferences of Puerto Ricans. DAIN also includes traditional foods commonly consumed in the typical Puerto Rican diet while maintaining the fundamental components of the IBD-AID™.

Crohn's disease is a chronic recurrent inflammatory disorder of the gastrointestinal that results from an inappropriate inflammatory response to an altered gut microbiome (i.e., dysbiosis). Diet is the main driver of microbiome composition. Diet also has been increasingly recognized as a cost-effective strategy to induce remission in pediatric and adult patients with Crohn's disease but diets that can substitute traditional and locally available foods among Puerto Ricans have not been explored. DAIN, a newly created dietary program, incorporates an extensive patient curriculum of recipes and menus adapted to the local availability and food preferences of Puerto Rican patients with Crohn's disease. This study aims to address three questions: whether DAIN a diet adapted to Puerto Rican patients with Crohn's disease, can: 1) induce clinical response and remission; 2) change the inflammatory tone, and 3) revert dysbiosis in Crohn's disease patients.

Participants will be randomized 1:1 ratio into two arms:

• Arm 1 Crohn's disease patients + DAIN (Experimental): this group of patients will participate in ten weeks of DAIN intervention (From week 1 to week 10)
• Arm 2 Crohn's disease patients no intervention (Control): this group of patients will not participate in the DAIN dietary intervention and will continue the usual diet.

Participation in the study lasts for 15 weeks with four-time points: week 0 (baseline), week 6, week 10, and week 14. At each time point, all subjects will complete a series of questionnaires to assess overall health, Crohn's disease activity, and dietary compliance. Blood and stool samples will be also collected at home at each time point. Samples will be either shipped or brought to the Research Unit at the Inflammatory Bowel Disease Clinic at the University of Puerto Rico.

The primary outcome is Improvement of health-related quality of life. Secondary outcomes are: (i) reduction of inflammation, (ii) changes in the gut microbiome, (iii) clinical response and remission,and (iii) dietary compliance.

Inclusion Criteria:

• 21 to 65 years old
• Confirmed CD diagnosis with sCDAI <450 (includes values ranging from remission, mild to moderate activity)
• Moderate to severe impaired QoL (sIBDQ<60)
• Stable doses of medications are screened; thiopurines, natalizumab, methotrexate (12 weeks), anti-tumor necrosis factor (TNF), ustekinumab, vedolizumab (8 weeks), 5-aminosalicylic acid (5-ASA) (2 weeks), steroids (1 week)
• Willingness and capacity to significantly change diet (arm 1)
• Willing and able to comply with specimen collection and other study procedures, and to complete the study

Exclusion Criteria:

• Ostomy
• Use of Specific Carbohydrate Diet of IBD-AID™ within 4 weeks of screening
• Use of prescribed probiotics within 4 weeks of screening
• > 20mg prednisone or equivalent
• Recent C. difficile colitis
• Pregnancy
• Presence of symptomatic or significant structure or history of obstruction in the past 6 months

All sequence data generated in this trial are understood to represent community resources and will be submitted to the appropriate public database. Specifically, data will be submitted to the NCBI (https://www.ncbi.nlm.nih.gov/), lncrnadb (http://www.lncrnadb.org/), and NONCODE (http://www.noncode.org/) databases as soon as sequencing data becomes available but not later than 2 years.

Sequence data will also include information on quality values for each sequence as well as required fields for metagenomic data. The study will be in compliance with the NIH Genomic Data Sharing (GDS).

Materials generated under the project will be disseminated in accordance with University/ Participating institutional and NIH policies.

2 years

Access to databases and associated software tools generated under the project will be available for educational, research and non-profit purposes. A portal will be created on the study website whereby anyone interested in collaborating or accessing to the data may submit a request form. Publication of data shall occur during the project, if appropriate, or at the end of the project, consistent with normal scientific practices. Research data, which documents, supports and validates research findings will be made available after the main findings from the final research data set have been accepted for publication. Such research data will be redacted to prevent the disclosure of personal identifiers.

All staff collecting data (e.g., dietary assessment) or assaying samples (e.g., fecal calprotectin, cytokines, sequencing) including the PI's, will be blinded to diet group assignments.