A Case-Based Approach to New Directions in Dietary Therapy of Crohn's Disease: Food for Thought

Progress and Clinical Applications of Crohn's Disease Exclusion Diet in Crohn's Disease

Crohn's disease is a chronic intestinal inflammatory disorder of unknown etiology. Although the pharmacotherapies for Crohn's disease are constantly updating, nutritional support and adjuvant therapies have recently gained more attention. Due to advancements in clinical nutrition, various clinical nutritional therapies are used to treat Crohn's disease. Doctors treating inflammatory bowel disease can now offer several diets with more flexibility than ever. The Crohn's disease exclusion diet is a widely used diet for patients with active Crohn's disease. The Crohn's disease exclusion diet requires both exclusion and inclusion. Periodic exclusion of harmful foods and inclusion of wholesome foods gradually improves a patient's nutritional status. This article reviews the Crohn's disease exclusion diet, including its structure, mechanisms, research findings, and clinical applications.

The Crohn's Disease Exclusion Diet: A Comprehensive Review of Evidence, Implementation Strategies, Practical Guidance, and Future Directions

Dietary therapy is increasingly recognized for the management of Crohn's disease (CD) over recent years, including the use of exclusive enteral nutrition (EEN) as first-line therapy for pediatric CD according to current guidelines. The Crohn's disease exclusion diet (CDED) is a whole-food diet designed to reduce exposure to dietary components that are potentially pro-inflammatory, mediated by negative effects on the gut microbiota, immune response, and the intestinal barrier. The CDED has emerged as a valid alternative to EEN with cumulative evidence, including randomized controlled trials, supporting use for induction of remission and possibly maintenance in children and adults. We gathered a group of multidisciplinary experts, including pediatric and adult gastroenterologists, inflammatory bowel diseases (IBD) expert dietitians, and a psychologist to discuss the evidence, identify gaps, and provide insights into improving the use of CDED based on a comprehensive review of CDED literature and professional experience. This article reviews the management of CDED in both children and adults, long-term aspects of CDED, indications and contraindications, selecting the best candidates, identifying challenges with CDED, globalization, the role of the multidisciplinary team, especially of dietitian, and future directions. We concluded that CDED is an established dietary therapy that could serve as an alternative to EEN in many pediatric and adult cases, especially with mild to moderate disease. In severe disease, complicated phenotypes, or with extraintestinal involvement, CDED should be considered on a case-by-case basis, according to physician and dietitians' discretion. More studies are warranted to assess the efficacy of CDED in different scenarios.

Effects of Crohn's disease exclusion diet on remission: a systematic review

Background

Dietary therapy may potentially reduce inflammation and promote mucosal healing in patients with Crohn's disease and is associated with fewer side effects and lower cost compared to medical therapy. Recently the Crohn's disease exclusion diet (CDED) has been developed to reduce exposure to individualized dietary components which negatively affect the intestine in patients with Crohn's disease.

Objectives

This systematic review aimed to explore the effectiveness of CDED in Crohn's disease patients.

Design

A systematic review.

Data sources and methods

A systematic search was performed on the PubMed, EBSCOhost, Cochrane library, OVID, Embase, Scopus, and CINHAL to identify relevant clinical trials published from 1 January 2014 to 31 August 2022.

Results

A total of 1120 studies were identified and 7 studies were finally included in the analysis. The study was reported according to Preferred Reporting Items for Systematic Reviews and Meta-analysis statement.

Conclusion

Our findings suggested that the use of CDED seemed to be effective for induction and maintenance of remission in children and adults with mild to moderate Crohn's disease. However, heterogeneity and limitations existed among the studies included. Further investigation in the form of well-designed randomized clinical trials is needed to validate the present findings.

Registration

PROSPERO registration number CRD42022335453.

Crohn's Disease Exclusion Diet for the Treatment of Crohn's Disease: Real-World Experience from a Tertiary Center

The Crohn's Disease (CD) exclusion diet (CDED) has been shown to induce remission in pediatric and adult patients with CD. In this retrospective cohort study, we describe our real-world experience with the CDED at the inflammatory bowel disease (IBD) unit of the Tel Aviv Medical Center between 2018-2021. CD patients with multiple clinical presentations and disease phenotypes who initiated the diet were included. Indications for treatment, medical and nutritional data were collected from dietician clinic visits and medical records. Clinical and biomarker responses were determined. The CDED was recommended to 220 CD patients. Seventy-two patients were included in the analysis for a clinically active disease (n = 48) or for remission maintenance (n = 24). Among patients with a clinically active disease, 62.5% of patients achieved clinical remission at week 6 and at week 12. A positive association between high adherence to the CDED and clinical remission at week 12 was observed (adjusted OR = 7.6, 95% CI 1.07-55.2, p = 0.043). Among patients treated for remission maintenance, remission at week 12 was maintained among 83.3% of patients. We conclude that the CDED may be a promising intervention for multiple CD presentations and indications. These findings should be further validated in larger, prospective, controlled studies.

Efficacy of Crohn's disease exclusion diet in treatment -naïve children and children progressed on biological therapy: a retrospective chart review

BACKGROUND

Recent trials suggested that the Crohn's disease (CD) exclusion diet (CDED) plus partial enteral nutrition (PEN) is a safe and effective strategy in remission induction of paediatric-onset CD. However, real-world evidence regarding the safety and efficacy of the CDED plus PEN approach is still lacking. The present case-series study reported our experience with the outcomes of CDED plus PEN in the paediatric-onset CD at disease onset and after the loss of response to biologics.

METHODS

We conducted a retrospective chart review on children who were treated with CDED plus PEN through the period from July 2019 and December 2020. Clinical and laboratory data were retrieved and compared at baseline, 6, 12, and 24 weeks of treatment. The primary endpoint of the present study was the rate of clinical remission.

RESULTS

The present study retrieved the data from 15 patients. Of them, nine patients were treatment naïve at the time of initiation of CDED plus PEN (group A) and the remaining patients relapsed on biologics before treatment. All patients in groups A and B exhibited clinical remission in week six, which was sustained until week 12. At the end of the follow-up, the clinical remission rate was 87% and 60% in groups A and B, respectively. No side effects were observed in both groups. In group A, the faecal calprotectin (FC) and albumin improved at week six, week 12, and week 24 (p < 0.05). The erythrocyte sedimentation rate (ESR) improved significantly at week 12 (p = 0.021) and week 24 (p = 0.027). At the same time, the haemoglobin and iron levels showed significant improvement only at week 24. For group B, only FC showed numerical reductions over time that did not reach the level of statistical significance.

CONCLUSION

Treatment with CDED plus PEN was well tolerated and achieved an excellent clinical remission rate in treatment-naive patients. However, the benefit of CDED plus PEN was less in patients who initiated the strategy after losing the response to biologics.

Insight into Inflammatory Bowel Disease Pathogenesis: Is the Answer Blowing in the Wind?

Inflammatory bowel diseases (IBD) including Crohn's disease and ulcerative colitis are conditions characterized by immune dysregulation to a trigger in those with a genetic predisposition. Environmental factors are thought to contribute to IBD, but no definite trigger has been identified. Aeroallergens have not been thoroughly investigated in their potential contribution to the pathogenesis to IBD. The geographic distribution of aeroallergens and IBD, the association of atopic disease with IBD, seasonality and IBD, and cross-reactive food allergens require further study with implications for targeted dietary and immunomodulatory therapies.

Modified Crohn's disease exclusion diet is equally effective as exclusive enteral nutrition: Real-world data

BACKGROUND

Data on the efficacy of the newly established dietetic treatment of Crohn's disease (CD), the CD exclusion diet (CDED), are scarce. The aim of this study was to provide real-world data on the efficacy of CDED in comparison with exclusive enteral nutrition (EEN) for remission induction.

METHODS

A retrospective analysis of children diagnosed with CD who were treated with CDED + partial EN (PEN) or with EEN was performed. Eighty percent of the children assigned to CDED + PEN underwent 1-2 weeks of EEN prior to CDED + PEN. For all children, data from the medical charts were extracted before the introduction of diet therapy and at the end of EEN or CDED + PEN phase 1.

RESULTS

A total of 61 patients (49.2% females; median age, 14.4 years [minimum: 6.7, maximum: 17.9]) were included in the study; 42 children (68.9%) achieved remission, 27 of 41 (65.9%) received EEN and 15 of 20 (75.0%) received CDED + PEN. There was no significant difference in the failure of nutrition therapy between the two groups (P = .469). Patients receiving CDED + PEN had significantly higher weight gain (P = .002) and increases in body mass index z-score (P = .001) compared with patients who received EEN alone.

CONCLUSION

Treatment with CDED + PEN (with prior 1-2 weeks of EEN) has comparable efficacy to EEN therapy alone in inducing remission in children with CD, and it leads to better weight gain. Further studies are needed to confirm these results.

Nutritional Interventions and the Gut Microbiome in Children

The gut microbiome plays an integral role in health and disease, and diet is a major driver of its composition, diversity, and functional capacity. Given the dynamic development of the gut microbiome in infants and children, it is critical to address two major questions: (a) Can diet modify the composition, diversity, or function of the gut microbiome, and (b) will such modification affect functional/clinical outcomes including immune function, cognitive development, and overall health? We synthesize the evidence on the effect of nutritional interventions on the gut microbiome in infants and children across 26 studies. Findings indicate the need to study older children, assess the whole intestinal tract, and harmonize methods and interpretation of findings, which are critical for informing meaningful clinical and public health practice. These findings are relevant for precision health, may help identify windows of opportunity for intervention, and may inform the design and delivery of such interventions. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The role of precision nutrition in the modulation of microbial composition and function in people with inflammatory bowel disease

Inflammatory bowel diseases, principally Crohn's disease and ulcerative colitis, are multifactorial chronic conditions. Alterations in gut microbial patterns partly affect disease onset and severity. Moreover, the evolution of dietary patterns, and their effect on gut microbial behaviour, have been shown to play a crucial role in disease processes. This Viewpoint reviews the role of dietary patterns, their influence on the structure and function of the gut microbiome, and their effects on inflammation and immunity in individuals with inflammatory bowel disease. We also discuss innovative dietary intervention strategies, summarise findings that have been used to develop recommendations for clinical practice, and provide suggestions for the design of future studies for development of precision nutrition in patients with inflammatory bowel disease.

Nutritional Therapy in Pediatric Crohn's Disease-Are We Going to Change the Guidelines?

In recent years, there has been a significant increase in the incidence of Crohn’s disease. Despite significant medical progress, the treatment options available today do not meet the needs of all patients. Recent reports indicate that external environmental factors, including diet, are key in the pathomechanism of the disease. It was proven that the so-called Western dietary pattern is associated with an increased risk of disease. In the pediatric population, exclusive enteral nutrition is the only nutritional therapy option recommended today with proven high efficacy in inducing remission. Recent publications that indicate at least comparable efficacy and significantly better tolerability of a specialised elimination diet, the Crohn’s Disease Exclusion Diet (CDED), provide the basis for a change in recommendations. This article discusses the mechanism of action, principles of use, and scientific evidence evaluating the efficacy of CDED in the treatment of children with Crohn’s disease.

Crohn's disease exclusion diet in children with Crohn's disease: a case series

Exclusive enteral nutrition (EEN) represents an established, evidence-based dietary therapy used in Crohn's disease (CD); although successful, EEN is extremely restrictive with limited acceptability and prolonged use. The Crohn's disease exclusion diet (CDED) is a new, sustainable and patient-friendly dietary therapy used for the management of pediatric CD. CDED is designed to reduce exposure to dietary components hypothesized to negatively affect the microbiome, intestinal barrier and immunity. By focusing on five clinical cases, this article illustrates the benefits of using CDED as mono- or co-therapy with partial enteral nutrition in children with mild to moderate CD. CDED combined with partial enteral nutrition is a safe and effective therapeutic option for both induction and maintenance therapy in children with mild to moderate CD. It ensures sustained remission and can induce mucosal healing in children with mild to moderate Crohn's disease.

Food and Food Groups in Inflammatory Bowel Disease (IBD): The Design of the Groningen Anti-Inflammatory Diet (GrAID)

Diet plays a pivotal role in the onset and course of inflammatory bowel disease (IBD). Patients are keen to know what to eat to reduce symptoms and flares, but dietary guidelines are lacking. To advice patients, an overview of the current evidence on food (group) level is needed. This narrative review studies the effects of food (groups) on the onset and course of IBD and if not available the effects in healthy subjects or animal and in vitro IBD models. Based on this evidence the Groningen anti-inflammatory diet (GrAID) was designed and compared on food (group) level to other existing IBD diets. Although on several foods conflicting results were found, this review provides patients a good overview. Based on this evidence, the GrAID consists of lean meat, eggs, fish, plain dairy (such as milk, yoghurt, kefir and hard cheeses), fruit, vegetables, legumes, wheat, coffee, tea and honey. Red meat, other dairy products and sugar should be limited. Canned and processed foods, alcohol and sweetened beverages should be avoided. This comprehensive review focuses on anti-inflammatory properties of foods providing IBD patients with the best evidence on which foods they should eat or avoid to reduce flares. This was used to design the GrAID.

Diet and Nutrition in Pediatric Inflammatory Bowel Diseases

Both genetic and environmental factors are involved in the onset of inflammatory bowel disease (IBD). In particular, diet composition is suspected to significantly contribute to IBD risk. In recent years, major interest has raised about the role of nutrition in disease pathogenesis and course, and many studies have shown a clear link between diet composition and intestinal permeability impairment. Moreover, many IBD-related factors, such as poor dietary intake, nutrients loss and drugs interact with nutritional status, thus paving the way for the development of many therapeutic strategies in which nutrition represents the cornerstone, either as first-line therapy or as reversing nutritional deficiencies and malnutrition in IBD patients. Exclusive enteral nutrition (EEN) is the most rigorously supported dietary intervention for the treatment of Crohn's Disease (CD), but is burdened by a low tolerability, especially in pediatric patients. Promising alternative regimens are represented by Crohn's Disease Exclusion Diet (CDED), and other elimination diets, whose use is gradually spreading. The aim of the current paper is to provide a comprehensive and updated overview on the latest evidence about the role of nutrition and diet in pediatric IBD, focusing on the different nutritional interventions available for the management of the disease.

Nutritional Therapy Strategies in Pediatric Crohn's Disease

The increase in incidences of pediatric Crohn's Disease (CD) worldwide has been strongly linked with dietary shifts towards a Westernized diet, ultimately leading to altered gut microbiota and disturbance in intestinal immunity and the metabolome. Multiple clinical studies in children with CD have demonstrated the high efficacy of nutritional therapy with exclusive enteral nutrition (EEN) to induce remission with an excellent safety profile. However, EEN is poorly tolerated, limiting its compliance and clinical application. This has spiked an interest in the development of alternative and better-tolerated nutritional therapy strategies. Several nutritional therapies have now been designed not only to treat the nutritional deficiencies seen in children with active CD but also to correct dysbiosis and reduce intestinal inflammation. In this review, we report the most recent insights regarding nutritional strategies in children with active CD: EEN, partial enteral nutrition (PEN), Crohn's disease exclusive diet (CDED), and CD treatment-with-eating diet (CD-TREAT). We describe their setup, efficacy, safety, and (dis)advantages as well as some of their potential mechanisms of action and perspectives. A better understanding of different nutritional therapeutic options and their mechanisms will yield better and safer management strategies for children with CD and may address the barriers and limitations of current strategies in children.

EEN Yesterday and Today … CDED Today and Tomorrow

The treatment of Pediatric Crohn’s Disease (CD) requires attention both to achieve mucosal healing and to optimize growth, while also maintaining proper bone health. Exclusive Enteral Nutrition (EEN) is recommended as first-line treatment in luminal CD. The therapeutic mechanisms of EEN are being discovered by advances in the study of the gut microbiota. Although the total exclusion of a normal diet during the time of EEN continues to be of high importance, new modalities of dietary treatment suggest a successful future for the nutritional management of CD. In this sense, Crohn’s Disease Exclusion Diet (CDED) is a long-term strategy, it apparently acts on the mechanisms that influence the appearance of inflammation (reducing dietary exposure to products negatively affecting the microbiota), but does so using specific available whole foods to achieve this goal, increases the time of clinical remission and promotes healthy lifestyle habits. The development of CDED, which partly minimizes the problems of EEN, has enabled a turnaround in the treatment of pediatric CD. This review highlights the role of enteral nutrition in the treatment of Crohn’s disease with special emphasis on newer dietary modalities such as CDED.

Nutritional Management of Paediatric Crohn’s Disease

For many people with Crohn’s disease (CD), onset occurs in childhood or adolescence. Treatment for CD has moved from predominantly surgical to, more often, pharmacological. While successful for many, others have tried various medications and combinations without long-term success and, for all, drug treatment needs to be balanced with potential therapy risks. Findings that diet can impact pathogenesis of CD to cause and exacerbate symptoms have inspired studies of dietary interventions. The Crohn’s Disease Exclusion Diet (CDED) was developed following the observation that certain dietary components were linked to inflammation and gut dysbiosis found in those with CD. This three-phase diet included two periods of a highly-controlled and prescribed diet, followed by a maintenance diet in which patients had a wider choice of foods. The diet limited ingestion of foods that may trigger inflammation and/or dysbiosis in CD, such as saturated fats, wheat, carrageenan, and some dairy products, and included healthy choices, such as fruits, vegetables, lean protein sources, and complex carbohydrates. It was nutritionally balanced, science-based, and included foods that were widely accessible. Based on findings from clinical trials and case studies, four experts (Prof Lionetti, Prof Martín-de-Carpi, Mrs Sigall-Boneh, and Prof Wine) discussed the background of CD, current treatment options, the utility of dietary therapies including CDED, and how all healthcare professionals (HCP) looking after children and adolescents with CD should consider the use of diet as part of their therapy.