Authors: Jana G. Hashash, Jaclyn Elkins, James D. Lewis, and David G. Binion
Journal: Gastroenterology
Year: 2024
Volume: 166
Pages: 521–532
DOI: 10.1053/j.gastro.2023.11.303
Study at a Glance
- Study type: Expert review
- Participants: Not applicable (expert guidance document)
- Population studied: Patients with inflammatory bowel disease (IBD)
- Intervention or approach studied: Diet and nutritional therapies, including Mediterranean diet, exclusive enteral nutrition, Crohn’s disease exclusion diet, and parenteral nutrition
- Comparison group: Various dietary approaches and usual care
- Follow-up duration: Not applicable
- Main outcome(s): Best practice advice statements for dietary management and nutritional therapy in IBD
Why Was This Study Done?
Diet plays an essential role for people with inflammatory bowel disease (IBD), yet guidance has been controversial and uncertain for both doctors and patients. Diet has been studied as both a risk factor for IBD development and a potential treatment for active disease. Dietary restrictions and IBD complications can lead to malnutrition, which is often unrecognised and untreated. This American Gastroenterological Association Clinical Practice Update provides practical advice on diet and nutritional therapies in IBD management, particularly for identifying and treating malnutrition.
How Was the Study Performed?
The expert review was commissioned and approved by the American Gastroenterological Association Clinical Practice Updates Committee and governing board, undergoing internal committee and external journal review. The authors developed 12 best practice advice statements by reviewing existing research and combining this with expert opinion. As this was not a systematic review, the authors did not formally rate evidence quality or recommendation strength.
What Did the Researchers Find?
Mediterranean Diet for General Health
The authors advised that all patients with IBD should follow a Mediterranean diet rich in fresh fruits and vegetables, healthy fats, complex carbohydrates, and lean proteins, whilst low in highly processed foods, added sugar, and salt. No single diet has consistently reduced flare rates in adults with IBD. A diet low in red and processed meat may reduce ulcerative colitis flares but not Crohn’s disease relapse.
Texture Modifications for Strictures
Patients with symptomatic bowel narrowing may not tolerate fibrous, plant-based foods. Careful chewing and cooking fruits and vegetables to a soft, less fibrous consistency may help these patients include more plant-based foods and fibre.
Exclusive Enteral Nutrition
Exclusive enteral nutrition, using liquid formulations as the only calorie source, effectively induces Crohn’s disease remission and improves endoscopic findings, with stronger evidence in children than adults. It may be considered as an alternative to steroids and may improve nutritional status and reduce surgical complications in malnourished patients before planned surgery.
Crohn’s Disease Exclusion Diet
The Crohn’s disease exclusion diet, combining liquid formulas with specific whole foods, may effectively induce remission and endoscopic response in mild to moderate Crohn’s disease of relatively short duration.
Parenteral Nutrition
Short-term parenteral nutrition is recommended for patients with abscesses or severe inflammation limiting adequate nutrition through the digestive system, providing bowel rest before surgery and potentially improving surgical outcomes. It is also recommended for high-output fistulae, prolonged bowel dysfunction, short bowel syndrome, and severe malnutrition when oral and tube feeding has failed. For short bowel syndrome, long-term parenteral nutrition should transition to customised hydration support and oral intake when possible, aided by glucagon-like peptide-2 agonists.
Malnutrition Screening
All patients with IBD should be regularly screened for malnutrition by assessing unintended weight loss, swelling, fluid retention, and fat and muscle mass loss, with complete evaluation by a registered dietitian when these are observed. Serum proteins are no longer recommended for identifying malnutrition due to lack of specificity and sensitivity to inflammation.
Micronutrient Monitoring
All patients with IBD should be monitored for vitamin D and iron deficiency. Those with extensive lower small intestine disease or prior surgery to this area should be monitored for vitamin B12 deficiency.
Role of Registered Dietitians
All outpatients and inpatients with complicated IBD should be managed with a registered dietitian, especially those with malnutrition, short bowel syndrome, fistulae, or requiring complex nutrition therapies. All newly diagnosed patients should have access to a registered dietitian.
Prevention
Breastfeeding is associated with lower childhood IBD risk. A healthy, balanced Mediterranean diet rich in fruits and vegetables with reduced highly processed foods has been associated with lower IBD development risk.
What Did the Authors Conclude?
The authors concluded that significant advances have been made in understanding diet and nutrition in IBD development and treatment. A healthy Mediterranean diet can be tolerated by many patients and may improve symptoms, particularly when introduced during remission or mild to moderate symptoms. Patients can be taught to modify fibrous food texture through cooking, blending, and thorough chewing to better tolerate a healthy diet. Liquid nutrition formulas show benefit for active inflammation or narrowing complications in Crohn’s disease, with exclusive enteral nutrition potentially inducing remission, strongest evidence being in children. Intravenous nutrition maintains an important role during acute complications when oral intake is unsafe. Dietary advice must be tailored to each patient’s nutritional status and goals, with complex nutritional strategies best achieved through collaborative working between gastroenterologists and registered dietitians.
Key Takeaways
- A Mediterranean diet rich in fruits and vegetables, healthy fats, and lean proteins, whilst low in processed foods, added sugar, and salt is recommended for patients with IBD for overall health and wellbeing.
- Exclusive enteral nutrition using liquid formulations is effective for inducing remission in Crohn’s disease, with stronger evidence in children, and may be used before surgery in malnourished patients to improve outcomes.
- All patients with IBD should be regularly screened for malnutrition through assessment of weight loss, swelling, and muscle and fat loss, with evaluation by a registered dietitian when these signs are present.
- Patients with IBD should be monitored for vitamin D and iron deficiency, and those with extensive lower small intestine disease or prior surgery should be monitored for vitamin B12 deficiency.
- Registered dietitians are essential members of the care team for patients with IBD, particularly those with complicated disease, malnutrition, or requiring complex nutritional therapies.
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.