Abstract

Background: The Crohn's disease exclusion diet (CDED) with partial enteral nutrition is effective for induction of remission in children with mild-to-moderate Crohn's disease. We aimed to assess the CDED in adults with Crohn's disease.

Methods: We did an open-label, pilot randomised trial at three medical centres in Israel. Eligible patients were biologic naive adults aged 18-55 years with mild-to-moderate Crohn's disease (defined by a Harvey-Bradshaw Index score of 5-14 points), a maximal disease duration of 5 years, with active disease on colonoscopy, or imaging with elevated inflammatory markers (C-reactive protein >5 mg/L or faecal calprotectin concentration >200 μ/g). Patients were randomly assigned (1:1) to CDED plus partial enteral nutrition or CDED alone for 24 weeks. Randomisation was via block randomisation (block sizes of six) using sealed, numbered, and opaque envelopes. Patients and investigators were aware of which group patients were assigned to due to the nature of the different interventions. The primary endpoint was clinical remission, defined as a Harvey-Bradshaw Index score of less than 5 at week 6. The primary endpoint was assessed in the intention-to-treat (ITT) population, which included all patients who used the dietary therapy for at least 48 h. We report results of the final analysis. This trial is registered with ClinicalTrials.gov, NCT02231814.

Findings: Between Jan 12, 2017, and May 11, 2020, 91 patients were screened, of whom 44 were randomly assigned to the CDED plus partial enteral nutrition group (n=20) or CDED alone group (n=24). 19 patients in the CDED plus partial enteral nutrition group and 21 patients in the CDED alone group received the allocated intervention for at least 48 h and thus were included in the ITT analysis. At week 6, 13 (68%) of 19 patients in the CDED plus partial enteral nutrition group and 12 (57%) of 21 patients in the CDED group had achieved clinical remission (p=0·4618). Among the 25 patients in remission at week 6, 20 (80%) were in sustained remission at week 24 (12 patients in the CDED plus partial enteral nutrition group and eight in the CDED alone group). 14 (35%) of 40 patients were in endoscopic remission at week 24 (eight patients in the CDED plus partial enteral nutrition group and six in the CDED alone group). No serious adverse events or treatment-related adverse events were reported in either group.

Interpretation: CDED with or without partial enteral nutrition was effective for induction and maintenance of remission in adults with mild-to-moderate biologic naive Crohn's disease and might lead to endoscopic remission. These data suggest that CDED could be used for mild-to-moderate active Crohn's disease and should be assessed in a powered randomised controlled trial.