Francesco Calabrese and colleagues from the University of Genoa have published a comprehensive review examining the role of diet as a potential therapeutic tool in inflammatory bowel disease. Their work, published in Digestive Diseases and Sciences in 2025, explores how various dietary approaches may influence symptoms, intestinal inflammation, the gut microbiome, and mucosal repair in both Crohn’s disease and ulcerative colitis.
Study at a Glance
- Study type: Narrative review
- Focus: Dietary interventions in inflammatory bowel disease
- Conditions covered: Crohn’s disease and ulcerative colitis
- Interventions examined: Exclusive enteral nutrition, Crohn’s disease exclusion diet, specific carbohydrate diet, Mediterranean diet, low-FODMAP diet, plant-based diets, and anti-inflammatory diet
- Main outcomes assessed: Clinical remission, symptom relief, adherence, microbiome changes, inflammatory markers
- Population: Adults and children with inflammatory bowel disease
Journal: Digestive Diseases and Sciences
Year: 2025
Authors: Francesco Calabrese, Andrea Pasta, Elena Formisano, Elisa Marabotto, Manuele Furnari, Livia Pisciotta, Patrizia Zentilin, Edoardo G. Giannini, Giorgia Bodini
DOI: https://doi.org/10.1007/s10620-025-09590-y
Why was this review done?
Diet may play a role beyond triggering symptoms in inflammatory bowel disease. Evidence links dietary patterns and nutrients to intestinal inflammation, gut bacteria composition, and mucosal repair. Despite advances in drug treatments, many patients fail to achieve sustained remission or experience medication side effects. Dietary therapy offers a pharmaceutical-free approach, particularly valuable for children where concerns exist about long-term safety of immune-suppressing drugs. The authors conducted this review to evaluate the role, efficacy, and patient acceptance of various diets in Crohn’s disease and ulcerative colitis.
How was the review performed?
Researchers searched PubMed and Embase for studies published up to 2025 examining dietary interventions in Crohn’s disease or ulcerative colitis. They included randomised controlled trials, cohort studies, systematic reviews, and significant case series reporting clinical outcomes such as remission rates, symptom scores, biomarker changes, adherence, or impacts on the microbiome. Both adult and paediatric populations were included. The authors organised diets by strength of evidence.
What did the authors find?
Exclusive enteral nutrition showed the strongest evidence. In children with active Crohn’s disease, it induces clinical remission in 60 to 80 per cent of cases, comparable to corticosteroids. One trial reported significantly higher mucosal healing rates at 8 weeks compared to steroids. It is recommended as first-line induction therapy in paediatric Crohn’s disease but is less commonly used in adults due to tolerance issues.
The Crohn’s disease exclusion diet restricts dairy, gluten, animal fats, red and processed meats, and artificial additives whilst emphasising easily digestible foods. Combined with partial enteral nutrition, a trial in children found more achieved remission at 12 weeks compared to exclusive enteral nutrition followed by food reintroduction. In adults, a pilot study found over 60 per cent achieved clinical remission after 6 weeks, with 80 per cent of responders sustaining remission through 24 weeks. By week 24, 35 per cent achieved endoscopic remission.
The specific carbohydrate diet eliminates most complex carbohydrates, refined sugars, and grains. A recent trial found it was not superior to the Mediterranean diet in achieving symptomatic remission at 6 weeks in adults with mild to moderate Crohn’s disease, with similar rates of 43 to 46 per cent.
The Mediterranean diet, characterised by high intake of fruits, vegetables, legumes, nuts, and whole grains with olive oil as primary fat, performed as well as the specific carbohydrate diet in producing symptom remission. Observational studies suggest greater adherence is associated with reduced risk of developing inflammatory bowel disease and milder disease course.
The low-FODMAP diet restricts fermentable carbohydrates. A trial found 50 to 60 per cent of patients with inflammatory bowel disease in remission reported adequate symptom relief compared to 16 per cent in the control group. Inflammatory markers remained stable, indicating functional rather than disease activity improvement.
A semi-vegetarian diet was examined in one small Crohn’s disease maintenance study. Over 2 years, only two of 16 adherent patients relapsed versus four of six on an omnivorous diet, achieving 92 per cent versus 33 per cent sustained remission rates.
Diets allowing greater flexibility, such as the Mediterranean diet or Crohn’s disease exclusion diet, achieved better long-term compliance than rigid regimens like exclusive enteral nutrition.
What did the authors conclude?
Calabrese and colleagues concluded that dietary therapy has moved from peripheral to prominent, supported by growing evidence. Efficacy is diet-specific and depends on disease characteristics: exclusive enteral nutrition remains most effective in paediatric Crohn’s disease, exclusion diets show promise in mild to moderate Crohn’s disease, whilst whole-food patterns suit selected ulcerative colitis cases or functional symptoms. Adherence remains the central limiting factor. Microbiome and biomarker-guided personalisation represents the logical next step, with emerging evidence suggesting specific signatures may help match diets to patients. Limitations include heterogeneous evidence and adherence barriers.
Key Takeaways
- Exclusive enteral nutrition induces remission in 60 to 80 per cent of children with active Crohn’s disease and is recommended as first-line induction therapy in this population.
- The Crohn’s disease exclusion diet combined with partial enteral nutrition shows promise for both inducing and maintaining remission in mild to moderate Crohn’s disease, with better adherence than exclusive enteral nutrition.
- The low-FODMAP diet effectively relieves functional symptoms such as bloating and abdominal pain in patients with inflammatory bowel disease in remission, without affecting disease activity.
- The Mediterranean diet may help prevent flares and support long-term health in inflammatory bowel disease, though it may not be powerful enough to induce remission in moderate to severe disease.
- Patient adherence remains the most significant barrier to successful dietary therapy, with more flexible diets generally achieving better long-term compliance than highly restrictive regimens.
This Scientific Publication Summary is an objective summary of the published study for personal and educational use. It does not constitute medical advice, endorsement of the intervention, or a recommendation to alter clinical practice.