Meta-Analysis: Crohn's Disease Exclusion Diet for Induction and Maintenance in Crohn's Disease

There is a contemporary interest in dietary therapies for the treatment of inflammatory bowel disease. We performed a systematic review and meta-analysis to analyse the clinical effectiveness of the Crohn's disease exclusion diet (CDED) for Crohn's disease (CD).

We searched PubMed, Embase, and Scopus on 10th February 2025 to identify relevant studies using the terms 'Inflammatory bowel disease OR Crohn's disease' AND 'Crohn's disease exclusion diet'. We extracted information and estimated pooled rates for clinical response, clinical remission, and maintenance of remission with CDED alone, or with partial enteral nutrition (PEN), or exclusive enteral nutrition (EEN). We calculated the odds ratio for outcomes with CDED as compared to controls. Risk of Bias was estimated using RoB-2.0, ROBINS-I, and Joanna Briggs appraisal tools.

Of the 508 titles, eventually 17 were included, and 16 studies provided quantitative data. The overall pooled rates for induction of clinical remission at 6-8 weeks with CDED-based interventions were 0.69 (95% CI: 0.65-0.74, I² = 0.0%). On subgroup analysis, pooled clinical remission rates for CDED+PEN, CDED alone and EEN induction+CDED+PEN were 0.69 (95% CI: 0.63-0.75, I² = 0.0%). 0.67 (95% CI: 0.57-0.76, I² = 0.0%), 0.75 (95% CI: 0.61-0.85, I² = 0.0%), respectively. The pooled rate of clinical response was 0.83 (0.74-0.89, I² = 0%) at 6 weeks. The pooled rate of maintenance of remission was 0.64 (0.47-0.78, I² = 73.5%). The overall odds of achieving clinical remission (2.58; 1.53-4.37, I² = 0%) were higher compared to the control diet. On comparison with EEN, steroids and Mediterranean diet, the odds ratio to achieve clinical remission (6-12 weeks) was 2.05 (95% CI: 1.13-3.74, I² = 0%), 17.33 (95% CI: 1.75-171), 3.95 (95% CI: 1.14-13.71, I2 = 0.0%), respectively. However, for clinical response (2.36; 95% CI: 0.62-9.00, I² = 42.4%), the odds ratio was not significantly different. For maintenance of remission, the pooled odds ratio was 2.73 (95% CI: 1.3-5.74, I² = 0%). Only limited data were available with respect to biochemical, endoscopic, transmural and histological outcomes.

CDED-based dietary interventions appear to be efficacious for inducing remission in Crohn's disease. Well-designed randomised trials are required to further validate the use of CDED as a whole food approach in the induction and maintenance of remission in Crohn's Disease.