Treatment of active Crohn's disease in children using partial enteral nutrition with liquid formula: a randomised controlled trial

Elemental Diet as a Therapeutic Modality: A Comprehensive Review

Elemental diets have been employed for the management of various diseases for over 50 years, with several mechanisms mediating their beneficial effects. Yet, they are underutilized due to poor palatability, access, cost, and lack of awareness regarding their clinical efficacy. Therefore, in this review, we aimed to systematically search and review the literature to summarize the formulation variability, mechanisms of action, clinical applications, and tolerability of the elemental diets in gastrointestinal diseases. While large prospective trials are lacking, elemental diets appear to exhibit objective and subjective clinical benefit in several diseases, including eosinophilic esophagitis, eosinophilic gastroenteritis, inflammatory bowel diseases, small intestinal bacterial overgrowth, intestinal methanogen overgrowth, chemoradiotherapy-associated mucositis, and celiac disease. Although some data support the long-term use of elemental diets as an add-on supplement for chronic pancreatitis and Crohn's disease, most of the literature on exclusive elemental diets focuses on inducing remission. Therefore, subsequent treatment strategies for maintaining remission need to be adopted in chronic/relapsing diseases. Several mechanistic pathways were identified to mediate the effects of elemental diets, including food additive and allergen-free content, high passive absorption rate, and anti-inflammatory properties. High rates of intolerance up to 40% are seen in the trials where exclusive elemental diets were administered orally due to poor organoleptic acceptability; however, when tolerated, adverse events were rare. Other limitations of elemental diets are cost, access, and lifestyle/social restrictions. Moreover, judicious use is advised in presence of a concomitant restrictive food intake disorders. Elemental diets offer a potentially highly efficacious dietary intervention with minor side effects. Palatability, cost, access, and social restrictions are common barriers of use. Prospective clinical trials are needed to elucidate the role of elemental formulas in the management of individual diseases.

Revolution in diet therapy for inflammatory bowel disease

Until recently, diet as a therapeutic tool to treat inflammatory bowel disease (IBD) has not been proven effective. Nearly a century in the making we are in the grips of a revolution in diet therapies for IBD, driven by emerging data revealing diet as a key environmental factor associated with IBD susceptibility, and observational studies suggesting that dietary intake may play a role in the disease course of established IBD. This review summarizes the current evidence for diets trialed as induction and maintenance therapy for IBD. For Crohn's disease, exclusive enteral nutrition and the Crohn's disease exclusion diet with partial enteral nutrition are supported by emerging high-quality evidence as induction therapy, but are short-term approaches that are not feasible for prolonged use. Data on diet as maintenance therapy for Crohn's disease are conflicting, with some studies supporting fortification, and others suppression, of certain food components. For ulcerative colitis, data are not as robust for diet as induction and maintenance therapy; however, consistent themes are emerging, suggesting benefits for diets that are plant-based, high in fiber and low in animal protein. Further studies for both Crohn's disease and ulcerative colitis are eagerly awaited, which will allow specific recommendations to be made. Until this time, recommendations default to population based healthy eating guidelines.

Role of diet in prevention versus treatment of Crohn's disease and ulcerative colitis

Diet is a modifiable risk factor for disease course and data over the past decade have emerged to indicate its role in Crohn's disease (CD) and ulcerative colitis (UC). However, literature is riddled with misinterpretation of data, often leading to unexpected or conflicting results. The key understanding is that causative factors in disease development do not always proceed to an opportunity to change disease course, once established. Here, we discuss the data on dietary influences in three distinct disease states for CD and UC-predisease, active disease and quiescent disease. We appraise the literature for how our dietary recommendations should be shaped to prevent disease development and if or how that differs for CD and UC induction therapy and maintenance therapy. In UC, principles of healthy eating are likely to play a role in all states of disease. Conversely, data linking dietary factors to CD prevention and treatment are paradoxical with the highest quality evidence for CD treatment being exclusive enteral nutrition, a lactose, gluten and fibre-free diet comprising solely of ultraprocessed food-all dietary factors that are not associated or inversely associated with CD prevention. High-quality evidence from dietary trials is much awaited to expand our understanding and ultimately lead our dietary recommendations for targeted patient populations.

Co-Development of Three Dietary Indices to Facilitate Dietary Intake Assessment of Pediatric Crohn's Disease Patients

Literature on dietary behaviours of the pediatric Crohn's Disease (CD) population and the relationship between dietary intake and CD activity is limited. Three dietary indices were developed and tested to conduct dietary pattern analysis in pediatric patients with CD consuming a free diet following remission induction via exclusive enteral nutrition (n = 11). Index scores underwent descriptive and inferential analysis. The mean adjusted scores (out of 100) for the Pediatric Western Diet Index, Pediatric Prudent Diet Index, and Pediatric-Adapted 2010 Alternate Healthy Eating Index (PA2010-AHEI) were 29.82 ± 15.22, 34.25 ± 15.18, and 51.50 ± 11.69, respectively. The mean Western-to-Prudent ratio was 0.94 ± 0.55. A significant correlation (r = -0.71) and relationship (F[1, 9] = 9.04, P < 0.05, R2 = 0.501) between the Western-to-Prudent ratio and PA2010-AHEI was found. The results suggest participants were not following a Western or Prudent diet, and were consuming foods not captured by the indices. More research is needed to describe dietary intake of individuals with CD, validate dietary indices in diverse samples, and explore the utility of these indices in CD assessment and treatment. The co-authors hope this work will stimulate/inspire subsequent interprofessional, dietitian-led research on this topic.

Surgical management of pediatric Crohn's disease

Management of pediatric-onset Crohn's disease uniquely necessitates consideration of growth, pubertal development, psychosocial function and an increased risk for multiple future surgical interventions. Both medical and surgical management are rapidly advancing; therefore, it is increasingly important to define the role of surgery and the breadth of surgical options available for this complex patient population. Particularly, the introduction of biologics has altered the disease course; however, the ultimate need for surgical intervention has remained unchanged. This review defines and evaluates the surgical techniques available for management of the most common phenotypes of pediatric-onset Crohn's disease as well as identifies critical perioperative considerations for optimizing post-surgical outcomes.

AGA Clinical Practice Update on Diet and Nutritional Therapies in Patients With Inflammatory Bowel Disease: Expert Review

DESCRIPTION

Diet plays a critical role in human health, but especially for patients with inflammatory bowel disease (IBD). Guidance about diet for patients with IBD are often controversial and a source of uncertainty for many physicians and patients. The role of diet has been investigated as a risk factor for IBD etiopathogenesis and as a therapy for active disease. Dietary restrictions, along with the clinical complications of IBD, can result in malnutrition, an underrecognized condition among this patient population. The aim of this American Gastroenterological Association (AGA) Clinical Practice Update (CPU) is to provide best practice advice statements, primarily to clinical gastroenterologists, covering the topics of diet and nutritional therapies in the management of IBD, while emphasizing identification and treatment of malnutrition in these patients. We provide guidance for tailored dietary approaches during IBD remission, active disease, and intestinal failure. A healthy Mediterranean diet will benefit patients with IBD, but may require accommodations for food texture in the setting of intestinal strictures or obstructions. New data in Crohn's disease supports the use of enteral liquid nutrition to help induce remission and correct malnutrition in patients heading for surgery. Parenteral nutrition plays a critical role in patients with IBD facing acute and/or chronic intestinal failure. Registered dietitians are an essential part of the interdisciplinary team approach for optimal nutrition assessment and management in the patient population with IBD.

METHODS

This expert review was commissioned and approved by the AGA Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the CPU Committee and external peer review through standard procedures of Gastroenterology. The best practice advice statements were drawn from reviewing existing literature combined with expert opinion to provide practical advice on the role of diet and nutritional therapies in patients with IBD. Because this was not a systematic review, formal rating of the quality of evidence or strength of the presented considerations was not performed. Best Practice Advice Statements BEST PRACTICE ADVICE 1: Unless there is a contraindication, all patients with IBD should be advised to follow a Mediterranean diet rich in a variety of fresh fruits and vegetables, monounsaturated fats, complex carbohydrates, and lean proteins and low in ultraprocessed foods, added sugar, and salt for their overall health and general well-being. No diet has consistently been found to decrease the rate of flares in adults with IBD. A diet low in red and processed meat may reduce ulcerative colitis flares, but has not been found to reduce relapse in Crohn's disease. BEST PRACTICE ADVICE 2: Patients with IBD who have symptomatic intestinal strictures may not tolerate fibrous, plant-based foods (ie, raw fruits and vegetables) due to their texture. An emphasis on careful chewing and cooking and processing of fruits and vegetables to a soft, less fibrinous consistency may help patients with IBD who have concomitant intestinal strictures incorporate a wider variety of plant-based foods and fiber in their diets. BEST PRACTICE ADVICE 3: Exclusive enteral nutrition using liquid nutrition formulations is an effective therapy for induction of clinical remission and endoscopic response in Crohn's disease, with stronger evidence in children than adults. Exclusive enteral nutrition may be considered as a steroid-sparing bridge therapy for patients with Crohn's disease. BEST PRACTICE ADVICE 4: Crohn's disease exclusion diet, a type of partial enteral nutrition therapy, may be an effective therapy for induction of clinical remission and endoscopic response in mild to moderate Crohn's disease of relatively short duration. BEST PRACTICE ADVICE 5: Exclusive enteral nutrition may be an effective therapy in malnourished patients before undergoing elective surgery for Crohn's disease to optimize nutritional status and reduce postoperative complications. BEST PRACTICE ADVICE 6: In patients with IBD who have an intra-abdominal abscess and/or phlegmonous inflammation that limits ability to achieve optimal nutrition via the digestive tract, short-term parenteral nutrition may be used to provide bowel rest in the preoperative phase to decrease infection and inflammation as a bridge to definitive surgical management and to optimize surgical outcomes. BEST PRACTICE ADVICE 7: We suggest the use of parenteral nutrition for high-output gastrointestinal fistula, prolonged ileus, short bowel syndrome, and for patients with IBD with severe malnutrition when oral and enteral nutrition has been trialed and failed or when enteral access is not feasible or contraindicated. BEST PRACTICE ADVICE 8: In patients with IBD and short bowel syndrome, long-term parenteral nutrition should be transitioned to customized hydration management (ie, intravenous electrolyte support and/or oral rehydration solutions) and oral intake whenever possible to decrease the risk of developing long-term complications. Treatment with glucagon-like peptide-2 agonists can facilitate this transition. BEST PRACTICE ADVICE 9: All patients with IBD warrant regular screening for malnutrition by their provider by means of assessing signs and symptoms, including unintended weight loss, edema and fluid retention, and fat and muscle mass loss. When observed, more complete evaluation for malnutrition by a registered dietitian is indicated. Serum proteins are no longer recommended for the identification and diagnosis of malnutrition due to their lack of specificity for nutritional status and high sensitivity to inflammation. BEST PRACTICE ADVICE 10: All patients with IBD should be monitored for vitamin D and iron deficiency. Patients with extensive ileal disease or prior ileal surgery (resection or ileal pouch) should be monitored for vitamin B12 deficiency. BEST PRACTICE ADVICE 11: All outpatients and inpatients with complicated IBD warrant co-management with a registered dietitian, especially those who have malnutrition, short bowel syndrome, enterocutaneous fistula, and/or are requiring more complex nutrition therapies (eg, parenteral nutrition, enteral nutrition, or exclusive enteral nutrition), or those on a Crohn's disease exclusion diet. We suggest that all newly diagnosed patients with IBD have access to a registered dietitian. BEST PRACTICE ADVICE 12: Breastfeeding is associated with a lower risk for diagnosis of IBD during childhood. A healthy, balanced, Mediterranean diet rich in a variety of fruits and vegetables and decreased intake of ultraprocessed foods have been associated with a lower risk of developing IBD.

Exclusive Enteral Nutrition Beneficially Modulates Gut Microbiome in a Preclinical Model of Crohn's-like Colitis

Exclusive enteral nutrition (EEN) is an established dietary treatment for Crohn's disease (CD) by alleviating inflammation and inducing remission. However, the mechanisms of action of EEN are incompletely understood. As CD is associated with gut microbiome dysbiosis, we investigated the effect of EEN on the microbiome in a rat model of CD-like colitis. The rat model of CD-like colitis was established by an intracolonic instillation of TNBS at 65 mg/kg in 250 µL of 40% ethanol. Sham control rats were instilled with saline. Rats were fed ad libitum with either regular pellet food or EEN treatment with a clear liquid diet (Ensure). Rats were euthanized at 7 days. Fecal pellets were collected from the distal colon for 16S rRNA sequencing analysis of gut microbiota. In addition, colon tissues were taken for histological and molecular analyses in all the groups of rats. EEN administration to TNBS-induced CD rats significantly improved the body weight change, inflammation scores, and disease activity index. The mRNA expression of IL-17A and interferon-γ was significantly increased in the colonic tissue in TNBS rats when fed with regular food. However, EEN treatment significantly attenuated the increase in IL-17A and interferon-γ in TNBS rats. Our 16S rRNA sequencing analysis found that gut microbiota diversity and compositions were significantly altered in TNBS rats, compared to controls. However, EEN treatment improved alpha diversity and increased certain beneficial bacteria such as Lactobacillus and Dubosiella and decreased bacteria such as Bacteroides and Enterorhabdus in CD-like rats, compared to CD-like rats with the regular pellet diet. In conclusion, EEN treatment increases the diversity of gut microbiota and the composition of certain beneficial bacteria. These effects may contribute to the reduced inflammation by EEN in the rat model of CD-like colitis.

Amino acid-based enteral nutrition is effective for pediatric Crohn's disease: a multicenter prospective study

Background

Exclusive enteral nutrition (EEN) therapy effectively induces remission in pediatric Crohn's disease (CD). However, this may depend on the type of enteral formula used. Moreover, data on the efficacy of amino acid-based EEN are limited. Thus, we aimed to prospectively evaluate the efficacy of amino acid-based formulas for EEN in pediatric patients with active CD.

Methods

Patients with active CD aged between 6 and 17 years were recruited into this prospective study from four hospitals in China between March 2019 and December 2021. Patients received EEN for 8 weeks. Inflammatory and nutrition-associated indices were evaluated at 0, 4, and 8 weeks after treatment. Paired t-tests and Wilcoxon signed-rank tests were used to compare continuous and categorical variables before and after intervention, respectively.

Results

Twenty-four patients were included in the analysis. After an 8-week intervention period, the CD activity index significantly decreased (26.3 ± 12.2 vs 7.1 ± 8.3, P < 0.001). Most patients (66.7%) achieved complete clinical remission. Among the 22 patients who had ulcers and erosions diagnosed endoscopically at baseline, 10 (45.5%) achieved complete mucosal healing. The degree of thickening of the intestinal wall was significantly reduced after EEN intervention, with a transmural healing rate of 42.9%. Furthermore, the serum inflammatory markers decreased and there was a significant improvement in the nutrition-related indices (P < 0.05). There were no severe adverse effects.

Conclusions

Amino acid-based EEN is effective and safe for treating pediatric-onset CD. Studies with larger sample sizes and mechanistic and follow-up studies are required to further validate these findings.

Treatment of Active Crohn's Disease in Children Using Partial Enteral Nutrition Combined with a Modified Crohn's Disease Exclusion Diet: A Pilot Prospective Cohort Trial on Clinical and Endoscopic Outcomes

BACKGROUND

Partial enteral nutrition (PEN) coupled with the Crohn's disease (CD) exclusion diet (CDED) was shown to be effective in inducing clinical remission in paediatric CD. There are currently no robust data on the endoscopic outcomes of PEN. The aim of this study was to evaluate the clinical and endoscopic rates of remission after PEN combined with a modified CDED (mCDED) adjusted to the local cuisine in comparison with exclusive enteral nutrition (EEN) for the induction of remission.

METHODS

Between June 2017 and February 2021, a prospective cohort study on children with active CD, treated with PEN + mCDED or EEN, was performed at a single tertiary centre.

RESULTS

During the study period, 54 patients were screened and 15 were excluded according to the exclusion criteria, with six patients excluded in the first two days due to intolerance of the enteral formula. Fourteen patients were included in the PEN and 19 in the EEN group. They were assessed at Weeks 0, 1, 3 and 6, using clinical and laboratory parameters. Endoscopy was performed at Weeks 0 and 6. Clinical remission rates per protocol analysis were 84.6% in the PEN group and 81.3% in the EEN group (p = 0.99). At Week 6, an endoscopic response (a decline in the Simple Endoscopic Score for CD (SES-CD) > 50%) was observed in 84.6% of patients on PEN and in 68.8% on EEN treatment (p = 0.41). Endoscopic remission (SES-CD ≤ 2) was achieved in 53.8% of patients in the PEN group and in 50.0% in the EEN group (p = 0.99), while the mucosal healing rates (SES-CD = 0) were 38.5% with PEN and 43.8% with EEN (p = 0.99). A significant decline in the clinical and endoscopic activity scores was observed in both groups.

CONCLUSION

Our study suggests that PEN + mCDED could be effective in inducing endoscopic remission and mucosal healing in active paediatric CD patients. Here, we present an analysis of the data from our cohort of patients and our real-world experience with PEN + mCDED.

Recent developments in the assessment and management of inflammatory bowel disease in childhood: a narrative review

Background and Objective

The landscape of paediatric inflammatory bowel disease (pIBD) continues to evolve in an era of increasing incidence. There have been rapid developments in understanding, as we begin to perceive IBD as a spectrum of conditions, alongside advancements in monitoring and treatment. The objective of this article was to provide an overview of recent advances and challenges in the management of pIBD, with a focus on sustainable healthcare, personalised therapy, genomics, new drugs and avenues for future optimisation.

Methods

We present a narrative review that synthesises and summarises recent research (2017-2022) related to pIBD. We undertook a structured search of the literature (PubMed and Medline) and additional articles were identified through manual searches of reference lists. Evidence tables were compiled for disease outcomes.

Key Content and Findings

In this review we outline current practice, integrating clinical guidelines and contemporary research. We discuss initial investigations (including suggested threshold for paediatric faecal calprotectin), specialist investigations for disease monitoring [with reference to video capsule endoscopy (VCE) and therapeutic drug levels] and outline new and established treatment options. Biomarkers and genomic testing are examined as important tools for individualising care and identifying potential therapeutic targets, including for top-down therapy. Despite these advances, significant challenges remain, including the need for further research to understand the mechanisms of disease and the translation of these advances into real-world improvements in practice.

Conclusions

Recent advances in understanding of the pathogenesis of pIBD, alongside genomic and pharmacological developments have added more tools to the armamentarium for the treatment of these conditions and highlighted ongoing areas of research need.

Microbiota signatures and mucosal healing in the use of enteral nutrition therapy v. corticosteroids for the treatment of children with Crohn's disease: a systematic review and meta-analysis

Corticosteroids (CS) and exclusive and partial enteral nutrition (EEN and PEN) are effective therapies in paediatric Crohn's disease (CD). This systematic review of randomised controlled trials (RCT) and cohort studies analyses the impact of EEN/PEN v. CS on intestinal microbiota, mucosal healing as well as other clinically important outcomes, including clinical remission, relapse, adherence, adverse events and health-related quality of life (HRQL) in paediatric CD. Three RCT (n 76) and sixteen cohort studies (n 1104) compared EEN v. CS. With limited available data (one RCT), the effect on intestinal microbiome indicated a trend towards EEN regarding Shannon diversity. Based on two RCT, EEN achieved higher mucosal healing than CS (risk ratio (RR) 2·36, 95 % CI (1·22, 4·57), low certainty). Compared with CS, patients on EEN were less likely to experience adverse events based on two RCT (RR 0·32, 95 % CI (0·13, 0·80), low certainty). For HRQL, there was a trend in favour of CS based on data from two published abstracts of cohort studies. Based on thirteen cohort studies, EEN achieved higher clinical remission than CS (RR 1·18, 95 % CI (1·02, 1·38), very low certainty). Studies also reported no important differences in relapse and adherence. Compared with CS, EEN may improve mucosal healing with fewer adverse events based on RCT data. While limited data indicate the need for further trials, this is the first systematic review to comprehensively summarise the data on intestinal microbiome, mucosal healing and HRQOL when comparing enteral nutrition and CS in paediatric CD.

Dietary Interventions for the Treatment of Inflammatory Bowel Diseases: An Updated Systematic Review and Meta-analysis

BACKGROUND & AIMS

This study aimed (1) to systematically review controlled trials of solid food diets for the treatment of inflammatory bowel disease (IBD); and (2) to grade the overall quality of evidence.

METHODS

Systematic review of prospective controlled trials of solid food diets for the induction or maintenance of remission in IBD. Two authors independently performed study selection, data extraction, and assessment of certainty of evidence. Meta-analyses were performed on studies with quantitative data on response, remission, and relapse.

RESULTS

There were 27 studies for meta-analysis. For induction of remission in Crohn's disease (CD), low refined carbohydrate diet and symptoms-guided diet outperformed controls, but studies had serious imprecision and very low certainty of evidence. The Mediterranean diet was similar to the Specific Carbohydrate Diet (low certainty of evidence), and partial enteral nutrition (PEN) was similar to exclusive enteral nutrition (very low certainty of evidence). PEN reduced risk of relapse (very low certainty of evidence), whereas reduction of red meat or refined carbohydrates did not (low certainty of evidence). For ulcerative colitis, diets were similar to controls (very low and low certainty of evidence).

CONCLUSIONS

Among the most robust dietary trials in IBD currently available, certainty of evidence remains very low or low. Nonetheless, emerging data suggest potential benefit with PEN for induction and maintenance of remission in CD. Reduction of red meat and refined carbohydrates might not reduce risk of CD relapse. As more dietary studies become available, the certainty of evidence could improve, thus allowing for more meaningful recommendations for patients.

The Role of Diet in Pediatric Inflammatory Bowel Disease

The pathogenesis of inflammatory bowel disease (IBD) involves a complex interaction between genetics, immune response, and the environment. Epidemiologic associations between diet and development of IBD plus the ability of diet to modify the microbiota and modulate immune function have led to the hypothesis that diet can prevent and/or treat IBD. It is well established that the induction of remission and healing of the mucosa in Crohn's disease can be accomplished with exclusive enteral nutrition. Whole food-based alternatives such as the Crohn's disease exclusion diet have shown promising results.

Nutrition, Nutritional Status, Micronutrients Deficiency, and Disease Course of Inflammatory Bowel Disease

During the disease course, most Inflammatory Bowel Disease patients present a condition of malnutrition, undernutrition, or even overnutrition. These conditions are mainly due to suboptimal nutritional intake, alterations in nutrient requirements and metabolism, malabsorption, and excessive gastrointestinal losses. A suboptimal nutritional status and low micronutrient serum levels can have a negative impact on both induction and maintenance of remission and on the quality of life of Inflammatory Bowel Disease patients. We performed a systematic review including all the studies evaluating the connection between nutrition, nutrition status (including undernutrition and overnutrition), micronutrient deficiency, and both disease course and therapeutic response in Inflammatory Bowel Disease patients. This systematic review was performed using PubMed/MEDLINE and Scopus. Four main clinical settings concerning the effect of nutrition on disease course in adult Inflammatory Bowel Disease patients were analyzed (induction of remission, maintenance of remission, risk of surgery, post-operative recurrence, and surgery-related complications). Four authors independently reviewed abstracts and manuscripts for eligibility. 6077 articles were found; 762 duplicated studies were removed. Out of 412 full texts analyzed, 227 were included in the review. The evidence summarized in this review showed that many nutritional aspects could be potential targets to induce a better control of symptoms, a deeper remission, and overall improve the quality of life of Inflammatory Bowel Disease patients.

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.

Role of Diet-Microbiome Interaction in Gastrointestinal Disorders and Strategies to Modulate Them with Microbiome-Targeted Therapies

Diet is an important determinant of health and consequently is often implicated in the development of disease, particularly gastrointestinal (GI) diseases, given the high prevalence of meal-related symptoms. The mechanisms underlying diet-driven pathophysiology are not well understood, but recent studies suggest that gut microbiota may mediate the effect of diet on GI physiology. In this review, we focus primarily on two distinct GI diseases where the role of diet has been best studied: irritable bowel syndrome and inflammatory bowel disease. We discuss how the concurrent and sequential utilization of dietary nutrients by the host and gut microbiota determines the eventual bioactive metabolite profiles in the gut and the biological effect of these metabolites on GI physiology. We highlight several concepts that can be gleaned from these findings, such as how distinct effects of an individual metabolite can influence diverse GI diseases, the effect of similar dietary interventions on multiple disease states, and the need for extensive phenotyping and data collection to help make personalized diet recommendations.

Role of Nutrition in Gastroesophageal Reflux, Irritable Bowel Syndrome, Celiac Disease, and Inflammatory Bowel Disease

There remains a paucity of data on the efficacy of nutritional interventions in luminal gastrointestinal disorders. This review appraises the evidence supporting dietary modification in gastroesophageal reflux disease (GERD), irritable bowel syndrome, Celiac disease, and inflammatory bowel disease. Alhough the use of elimination diets; high fat/low carb; low fermentable oligosaccharides, disaccharides, monosaccharides and polyols; and lactose-free diets in GERD have been studied, the evidence supporting their efficacy remains weak and mixed. Patients with GERD should avoid eating within 3 hours of lying recumbent. Studied dietary interventions for disorders of gut-brain interaction include low fermentable oligosaccharides, disaccharides, monosaccharides and polyols and gluten-restricted and lactose-free diets. While all can be effective in carefully, individually selected patients, the evidence for each intervention remains low. In patients with inflammatory bowel disease, enteral nutrition is established in pediatric populations as useful in reducing inflammation and partial enteral nutrition has a growing evidence base for use in adults and children. Specific carbohydrate diets and the Crohn's disease exclusion diet show promising evidence but require further study to validate their efficacy prior to recommendation. Overall, the evidence supporting nutritional therapy across luminal gastrointestinal disorders is mixed and often weak, with few well-designed randomized controlled trials (RCTs) demonstrating consistent efficacy of interventions. RCTs, particularly cross-over RCTs, show potential to compare dietary interventions.

ESPEN guideline on Clinical Nutrition in inflammatory bowel disease

The present guideline is an update and extension of the ESPEN scientific guideline on Clinical Nutrition in Inflammatory Bowel Disease published first in 2017. The guideline has been rearranged according to the ESPEN practical guideline on Clinical Nutrition in Inflammatory Bowel Disease published in 2020. All recommendations have been checked and, if needed, revised based on new literature, before they underwent the ESPEN consensus procedure. Moreover, a new chapter on microbiota modulation as a new option in IBD treatment has been added. The number of recommendations has been increased to 71 recommendations in the guideline update. The guideline is aimed at professionals working in clinical practice, either in hospitals or in outpatient medicine, and treating patients with IBD. General aspects of care in patients with IBD, and specific aspects during active disease and in remission are addressed. All recommendations are equipped with evidence grades, consensus rates, short commentaries and links to cited literature.

Current Nutritional Therapies in Inflammatory Bowel Disease: Improving Clinical Remission Rates and Sustainability of Long-Term Dietary Therapies

Inflammatory Bowel Disease (IBD) includes a spectrum of chronic immune-mediated intestinal diseases thought to be related to the complex interaction between the host immune system and the intestinal microbiome. Research supports the use of nutritional therapy in IBD; however, it is not routinely used in clinical practice. This literature review seeks to advance the understanding of diet and its effect in IBD with a focus on both Crohn's Disease (CD) and Ulcerative Colitis (UC). The contribution of diet to the development and treatment of IBD cannot be overstated. In both pediatric as well as adult IBD, nutritional interventions have been shown to improve clinical symptoms as well as inflammatory burden. The impact of dietary intervention is best exemplified through the use of Exclusive Enteral Nutrition (EEN) in CD. EEN and clinical research on exclusionary whole food diets-Crohn's Disease Exclusion Diet (CDED), Specific Carbohydrate Diet (SCD), low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet, and Mediterranean Diet-are discussed within this review. Current clinical literature supports the elimination of detrimental components and the incorporation of low processed whole foods in the diet. Additional prospective and longitudinal dietary studies on sustainable and long-term dietary options, along with a deeper understanding of the mechanism, are needed to further advance the role of nutritional interventions in IBD.

Repeated and multiple fecal microbiota transplantations plus partial enteral nutrition as the first-line treatment in active pediatric Crohn's disease

Background

Most studies have reported fecal microbiota transplantation (FMT) as an effective secondary option for Crohn's disease (CD). However, there is little data on FMT as a first-line treatment for CD. In our study we explore the rates of clinical and endoscopic remission and mucosal healing after FMT plus partial enteral nutrition (PEN), as a first-line treatment for active CD in children.

Methods

We retrospectively enrolled pediatric CD patients who underwent PEN or PEN plus FMT treatment at diagnosis from November 2016 to July 2019 at the Pediatric Department, Tongji Hospital. The two groups were defined as FMT group (repeated and multiple doses of FMT plus PEN) or PEN group (PEN alone). All the patients received PEN intervention. At baseline and week 8- 10, the FMT group was administered multiple doses of FMT to help induce and maintain remission. All patients were evaluated at week 8- 10 and 18-22 via clinical and relevant laboratory parameters and endoscopic results. The clinical and endoscopic remission and mucosal healing rates were compared between the two groups at different time points after the therapy.

Results

Twenty-five newly diagnosed active CD patients were included in the study, containing 7 females and 18 males with a median age of 11. 1 ± 2.3 years. 13 and 12 patients were assigned to the PEN and FMT groups, respectively. At week 8-10, clinical remission was obtained in 83.3% and 53.8% of the FMT and PEN groups, respectively (p=0.202). The endoscopic remission rates were 72.7% for FMT and 25.0% for PEN (p=0.039), whereas the mucosal healing rates were 27.2% for FMT and 0% for PEN (p=0.093). At week 18-22, clinical remission was achieved in 72.7% and 20.0% of patients in the FMT and PEN groups, respectively (p=0.03). Theendoscopic remission rates were 66.6% and 12.5% in the FMT and PEN groups, respectively (p=0.05), whereas the mucosal healing rates were 55.5% and 0% in FMT and PEN groups, respectively (p=0.029).

Conclusion

This study demonstrate that FMT plus PEN can be used as a first-line treatment for active CD in children.

The Role of Partial Enteral Nutrition for Induction of Remission in Crohn's Disease: A Systematic Review of Controlled Trials

Exclusive enteral nutrition (EEN) is recommended as a first-line therapy to induce remission of Crohn's disease (CD) and is considered as effective as corticosteroid treatment. However, the dietary restriction causes lack of adherence and poor tolerance to the therapy. Partial enteral nutrition (PEN), which allows for the ingestion of some food, could be a better tolerated alternative, but it is unknown whether it is as effective at inducing CD remission as EEN. The aim of this systematic review is to analyze the available evidence on PEN as a remission induction therapy in CD. A literature search was conducted using the MEDLINE (via PUBMED) and Cochrane Library databases following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Clinical trials in pediatric and adult patients were included. The risk of bias was assessed following the Cochrane Collaboration methodology. The selected studies showed variable but high response rates to PEN and EEN. Limitations regarding the wide heterogeneity between the studies included in this review should be considered. Although more studies are needed, according to our results, PEN combined with a highly restrictive diet seems to be as effective as EEN in inducing remission of CD.

Global attitudes on and the status of enteral nutrition therapy for pediatric inflammatory bowel disease

Enteral nutrition (EN) is a diet-remission therapy for inflammatory bowel disease (IBD) that plays a more important role in children than adults. EN includes exclusive enteral nutrition (EEN), partial enteral nutrition (PEN), and maintenance enteral nutrition (MEN). However, EEN remains an unstandardized treatment for pediatric IBD. The types and methods of EN differ around the world. The current study reviewed the EN literature on children with IBD. A total of 12 survey studies were identified that analyzed the current state of EN use, including clinical opinions, implementation methods, treatment course, EEN formula, IBD classification, progress, dietary reintroduction, and patient feedback. The findings revealed that EEN has a strong effect on mild to moderate Crohn's disease (CD). The usage rates of this treatment in different sites were ileum/colon (Paris classification L3) > ileum (L1) > upper digestive tract (L4) > colon (L2) > perianal disease (P) > ulcerative colitis (UC) > extraintestinal lesions. The polymeric formula was the most used EN formulation. New EN diets include a CD exclusion diet (CDED), a specific carbohydrate diet (SCD), and a CD treatment-with-eating (CD-TREAT) diet. Children with IBD responded similarly to EEN administered orally or using a feeding tube. Most guidelines recommended 6-8 weeks of EEN treatment to induce remission. Many clinicians preferred to combine drug medications during EEN and recommended that MEN accounts for at least 25-35% of daily caloric intake. EN remains an unstandardized therapy that requires teamwork across disciplines.

Diet fuelling inflammatory bowel diseases: preclinical and clinical concepts

The diet and gut microbiota have been extensively interrogated as a fuel for gut inflammation in inflammatory bowel diseases (IBDs) in the last few years. Here, we review how specific nutrients, typically enriched in a Western diet, instigate or deteriorate experimental gut inflammation in a genetically susceptible host and we discuss microbiota-dependent and independent mechanisms. We depict the study landscape of nutritional trials in paediatric and adult IBD and delineate common grounds for dietary advice. Conclusively, the diet reflects a critical rheostat of microbial dysbiosis and gut inflammation in IBD. Dietary restriction by exclusive enteral nutrition, with or without a specific exclusion diet, is effectively treating paediatric Crohn's disease, while adult IBD trials are less conclusive. Insights into molecular mechanisms of nutritional therapy will change the perception of IBD and will allow us to enter the era of precision nutrition. To achieve this, we discuss the need for carefully designed nutritional trials with scientific rigour comparable to medical trials, which also requires action from stake holders. Establishing evidence-based dietary therapy for IBD does not only hold promise to avoid long-term immunosuppression, but to provide a widely accessible therapy at low cost. Identification of dietary culprits disturbing gut health also bears the potential to prevent IBD and allows informed decision making in food politics.

Pilot study of an elimination diet in adults with mild to moderate Crohn's disease

BACKGROUND

There remains limited data supporting the efficacy of dietary therapy in adults with Crohn's disease (CD). This was a pilot study of the McMaster Elimination diet for CD (MED-CD), which excludes several potentially detrimental ingredients commonly found in the Western diet.

METHODS

Prospective study in adults with mild-moderately active CD [Harvey-Bradshaw Index (HBI) scores 5-16] and endoscopic disease activity of >7 (or ≥4 for isolated ileal disease) as measured by the Simple Endoscopic Score for Crohn's disease (SES-CD). Patients were treated for 2 weeks using oral enteral nutrition (EN). Those with symptomatic improvement (HBI score reduction ≥2) were transitioned to the MED-CD for 12 weeks. Outcomes of interest included satisfactory adherence (≥20 on the modified medical adherence report scale-5 questionnaire), clinical remission (CR) (HBI ≤4), clinical response (HBI reduction ≥3), endoscopic response (SES-CD reduction ≥50%), and endoscopic remission (ER) (SES-CD <3).

RESULTS

A total of 17 patients were treated with 2 weeks of EN. Of these, 13 were deemed responders and treated with 12 weeks of MED-CD. Satisfactory adherence was reported among 11/13 (84.6%) at week 6 and 8/12 (67%) at week 14. Of the 13 patients who responded to EN by week 2, 5 (38.5%) had attained CR at week 2 and maintained CR until week 14 using MED-CD. Endoscopic response was observed in 6 (46.2%) participants and ER was seen in 2 (15.4%).

CONCLUSIONS

Two weeks of oral EN followed by 12 weeks of the MED-CD was acceptable by most adult patients who enroled in this study.

Selected Aspects of Nutrition in the Prevention and Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease has become a global health problem at the turn of the 21st century. The pathogenesis of this disorder has not been fully explained. In addition to non-modifiable genetic factors, a number of modifiable factors such as diet or gut microbiota have been identified. In this paper, the authors focus on the role of nutrition in the prevention of inflammatory bowel disease as well as on the available options to induce disease remission by means of dietary interventions such as exclusive and partial enteral nutrition in Crohn's disease, the efficacy of which is reported to be comparable to that of steroid therapy. Diet is also important in patients with inflammatory bowel disease in the remission stage, during which some patients report irritable bowel disease-like symptoms. In these patients, the effectiveness of diets restricting the intake of oligo-, di-, monosaccharides, and polyols is reported.

Dietary Therapy to Improve Nutrition and Gut Health in Paediatric Crohn’s Disease; A Feasibility Study

Bovine colostrum (BC) has anti-inflammatory, anti-infective, growth and intestinal repair factors that may be beneficial in Crohn’s disease (CD). We assessed whether daily BC for up to 3 months was acceptable to children and young people (CYP) with CD in remission or of mild/moderate severity. CYP were randomised to receive either BC or matching placebo milk daily for 6 weeks (blinded phase); all received BC for the following 6 weeks (open phase). In 23 CYP, median (inter-quartile range) age was 15.2 (13.9–16.1) years and 9 (39.1%) were girls. A similar proportion of CYP in the BC and placebo arms completed the blinded phase (8/12, 75.0% and 9/11, 81.8% respectively). Twelve (70.6%) CYP completed the open phase with 7 (58.3%) tolerating BC for 3 months. Diaries in weeks 2, 6 and 12 revealed that most CYP took BC every day (5/7, 71.4%; 5/8, 62,5% and 6/11, 54.5% respectively). In interviews, opinions were divided as to preference of BC over the placebo milk and some preferred BC over other nutritional supplements. Symptoms, clinical and laboratory variables and quality of life were similar in the two arms. BC may be an acceptable nutritional supplement for daily, longer-term use in CYP with CD.

Crohn’s Disease, Host–Microbiota Interactions, and Immunonutrition: Dietary Strategies Targeting Gut Microbiome as Novel Therapeutic Approaches

Crohn’s disease (CD) is a complex, disabling, idiopathic, progressive, and destructive disorder with an unknown etiology. The pathogenesis of CD is multifactorial and involves the interplay between host genetics, and environmental factors, resulting in an aberrant immune response leading to intestinal inflammation. Due to the high morbidity and long-term management of CD, the development of non-pharmacological approaches to mitigate the severity of CD has recently attracted great attention. The gut microbiota has been recognized as an important player in the development of CD, and general alterations in the gut microbiome have been established in these patients. Thus, the gut microbiome has emerged as a pre-eminent target for potential new treatments in CD. Epidemiological and interventional studies have demonstrated that diet could impact the gut microbiome in terms of composition and functionality. However, how specific dietary strategies could modulate the gut microbiota composition and how this would impact host–microbe interactions in CD are still unclear. In this review, we discuss the most recent knowledge on host–microbe interactions and their involvement in CD pathogenesis and severity, and we highlight the most up-to-date information on gut microbiota modulation through nutritional strategies, focusing on the role of the microbiota in gut inflammation and immunity.

6- and 12-Month Outcomes after 90:10 Enteral Nutrition Induction Therapy in Pediatric Crohn's Disease

OBJECTIVES

Studies describing longer-term outcomes after EEN induction are limited. We describe clinical outcomes during 90:10 EN induction, and 6- and 12- month outcomes among patients that successfully completed EN induction and then continued either EN or immunomodulator (IM) maintenance therapy.

METHODS

All children with CD treated with 90:10 EN induction protocol (90% formula:10% regular diet) at our IBD Center from 2013 to 2018 were retrospectively reviewed. Demographic, clinical, and laboratory data were recorded at baseline, 6, and 12 months (± 3 months at each timepoint). Therapy changes after initiation of EN induction through 12 months were recorded. Among patients that successfully completed 90:10 induction, outcomes between EN and IM maintenance groups were compared.

RESULTS

In total, 44/105 (42%) patients completed 8-12 weeks of 90:10 EN induction. Sixty-one patients had incomplete EN induction, with 52% requiring corticosteroids and 25% anti-TNF therapy as alternate induction approaches. Forty-four patients completed EN induction (18 continued EN maintenance and 26 IM maintenance therapy). Twenty-seven of these 44 (61%) remained on initial maintenance therapy at 6 months (10/18 (56%) EN and 17/26 (65%) IM). In total, 16/44 (36%) remained on their initial maintenance therapy at 12 months. By 12 months, 10 patients required anti-TNF and 11 corticosteroids after successful completion of induction.

CONCLUSIONS

In this retrospective study of short and longer-term outcomes after 90:10 EN induction, the need for an alternate induction therapy was common, most frequently to anti-TNF or corticosteroid therapy. Future studies are needed to evaluate for predictors of long-term success after EN induction.

The Impact of Compliance During Exclusive Enteral Nutrition on Faecal Calprotectin in Children With Crohn Disease

It remains unclear whether suboptimal response to exclusive enteral nutrition (EEN) in some children with Crohn disease (CD) is explained by poor compliance. The present study measured faecal gluten immunogenic peptides (GIP), a biomarker of gluten intake, in 45 children (3- 17 years) with CD, and explored associations with faecal calprotectin (FC) levels at 33 and 54 days of EEN. FC decreased in patients with undetectable GIP at both 33 and 54 days of EEN (mean decrease, 33 days: -743 mg/kg, 54 days: -1043 mg/kg, P  < 0.001) but not in patients who had detectable levels. At EEN completion, patients with undetectable GIP had a lower FC by 717 mg/kg compared with patients with a positive GIP result (P = 0.042) and demonstrated a greater decline from baseline FC (-69% vs +5%, P = 0.011). Poorer response to EEN is explained in part by diminished compliance. Faecal GIP might be useful as proxy biomarker of EEN compliance.

Pediatric Management of Crohn's Disease

Pediatric Crohn's disease is often more severe, requires higher levels of immunosuppression, and is associated with greater morbidity compared with adult Crohn's disease. Unique considerations in pediatric Crohn's disease include growth impairment, pubertal delay, bone disease, longevity of disease burden, and psychosocial impact. Treatment options are limited, requiring off-label use of therapy in this challenging patient population. Understanding the medications available, the existing evidence supporting their use, and side effects is important. There is tremendous potential for growth and improvement in this field and it is essential that all gastroenterologists have an understanding of this complex and unique patient population.

Exclusive enteral nutrition: An optimal care pathway for use in children with active luminal Crohn's disease

AIM

Exclusive enteral nutrition (EEN) is recommended as a first-line therapy for active luminal paediatric Crohn's disease, by many contemporary consensus guidelines. However, EEN protocols vary internationally. A key enabler for the use of EEN therapy has been identified as the standardisation of protocols. The aim of this study was to develop an optimal care pathway for use of EEN in children with active luminal Crohn's disease.

METHODS

A working group of 11 paediatric gastroenterology dietitians and one paediatric gastroenterologist from Australia and New Zealand was convened to develop a standard optimal care pathway. Seven key areas were identified; clinical indications, workup assessments, EEN prescription, monitoring, food reintroduction, partial enteral nutrition and maintenance enteral nutrition. Recent literature was reviewed, assessed according to the National Health and Medical Research Council guidelines, and consensus statements were developed and voted on. Consensus opinion was used where literature gaps existed.

RESULTS

A total of nineteen consensus statements from the seven key areas were agreed upon. The consensus statements informed the optimal care pathway for children with active luminal undertaking EEN in Australia and New Zealand.

CONCLUSION

This study developed an EEN optimal care pathway to facilitate standardisation of clinical care for children with active luminal Crohn's disease, and hopefully improve clinical outcomes and identify areas for future research.

Long-term exclusive enteral nutrition remodels gut microbiota and alleviates TNBS-induced colitis in mice

Exclusive enteral nutrition (EEN) provides an effective strategy for the induction of clinical remission in pediatric Crohn’s disease. However, the feasibility of long-term EEN in management of disease and the...

Diet and microbiome in the beginning of the sequence of gut inflammation

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract due, at least partially, to an aberrant and excessive mucosal immune response to gut bacteria in genetically-predisposed individuals under certain environmental factors. The incidence of IBD is rising in western and newly industrialized countries, paralleling the increase of westernized dietary patterns, through new antigens, epithelial function and permeability, epigenetic mechanisms (e.g., DNA methylation), and alteration of the gut microbiome. Alteration in the composition and functionality of the gut microbiome (including bacteria, viruses and fungi) seems to be a nuclear pathogenic factor. The microbiome itself is dynamic, and the changes in food quality, dietary habits, living conditions and hygiene of these western societies, could interact in a complex manner as modulators of dysbiosis, thereby influencing the activation of immune cells' promoting inflammation. The microbiome produces diverse small molecules via several metabolic ways, with the fiber-derived short-chain fatty acids (i.e., butyrate) as main elements and having anti-inflammatory effects. These metabolites and some micronutrients of the diet (i.e., vitamins, folic acid, beta carotene and trace elements) are regulators of innate and adaptive intestinal immune homeostasis. An excessive and unhealthy consumption of sugar, animal fat and a low-vegetable and -fiber diet are risk factors for IBD appearance. Furthermore, metabolism of nutrients in intestinal epithelium and in gut microbiota is altered by inflammation, changing the demand for nutrients needed for homeostasis. This role of food and a reduced gut microbial diversity in causing IBD might also have a prophylactic or therapeutic role for IBD. The relationship between dietary intake, symptoms, and bowel inflammation could lead to dietary and lifestyle recommendations, including diets with abundant fruits, vegetables, olive oil and oily fish, which have anti-inflammatory effects and could prevent dysbiosis and IBD. Dietary modulation and appropriate exclusion diets might be a new complementary management for treatment at disease flares and in refractory patients, even reducing complications, hospitalizations and surgery, through modifying the luminal intestinal environment.

Nutritional Therapies and Their Influence on the Intestinal Microbiome in Pediatric Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic, autoimmune disorder of the gastrointestinal tract with numerous genetic and environmental risk factors. Patients with Crohn’s disease (CD) or ulcerative colitis (UC) often demonstrate marked disruptions of their gut microbiome. The intestinal microbiota is strongly influenced by diet. The association between the increasing incidence of IBD worldwide and increased consumption of a westernized diet suggests host nutrition may influence the progression or treatment of IBD via the microbiome. Several nutritional therapies have been studied for the treatment of CD and UC. While their mechanisms of action are only partially understood, existing studies do suggest that diet-driven changes in microbial composition and function underlie the diverse mechanisms of nutritional therapy. Despite existing therapies for IBD focusing heavily on immune suppression, nutrition is an important treatment option due to its superior safety profile, potentially low cost, and benefits for growth and development. These benefits are increasingly important to patients. In this review, we will describe the clinical efficacy of the different nutritional therapies that have been described for the treatment of CD and UC. We will also describe the effects of each nutritional therapy on the gut microbiome and summarize the strength of the literature with recommendations for the practicing clinician.

Effectiveness of Crohn's Disease Exclusion Diet for Induction of Remission in Crohn's Disease Adult Patients

Exclusive enteral nutrition (EEN) is a first-line treatment in active, mild to moderate Crohn’s disease (CD) in children. The Crohn’s disease exclusion diet (CDED), which avoids products known to have a pro-inflammatory effect on the intestinal mucosa, presents similar effectiveness to EEN for inducing remission in the paediatric population. The aim of the study was to evaluate the effectiveness of the CDED in inducing remission in adult patients. Between March 2020 and May 2021, 32 patients in a gastroenterology outpatient centre were treated according to the assumptions of the CDED. The patients were seen at baseline, at week 6, and at week 12 of the study. During the visits, anthropometric measurements and laboratory tests were performed, Crohn’s disease activity index (CDAI) was calculated, and the Inflammatory Bowel Disease Questionnaire (IBDQ) was completed. The study included a total of 32 participants, 18 women (56.3%) and 14 men (43.7%). Clinical remission was obtained in 76.7% patients after 6 weeks and in 82.1% after 12 weeks of therapy. Calprotectin levels were significantly lower in the second follow-up compared with baseline (p = 0.021). The CDED is an effective therapy for inducing remission in the adult CD population.

The Crohn's disease exclusion diet for induction and maintenance of remission in adults with mild-to-moderate Crohn's disease (CDED-AD): an open-label, pilot, randomised trial

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.

FUNDING

Azrieli Foundation and Nestle Health Science.

Diet and gut microbiota manipulation for the management of Crohn's disease and ulcerative colitis

The aetiology of inflammatory bowel disease (IBD) is multifactorial, with diet and gut microbiota playing an important role. Nonetheless, there are very few studies, particularly clinical research, which have explored the interaction between diet and gut microbiota. In the current review, we summarise the evidence from clinical trials exploring the interactions between the gut microbiota and diet in the management of IBD. Data from the effect of exclusive enteral nutrition (EEN) on the gut microbiota of children with active Crohn's disease (CD), receiving induction treatment, offer opportunities to understand the role of gut microbiota in underlying disease pathogenesis and develop novel dietary and pharmacological microbial therapeutics. In contrast, the evidence which links the effectiveness of food-based dietary therapies for IBD with mechanisms involving the gut microbiota is far less convincing. The microbial signals arising from these dietary therapies are inconsistent and vary compared to the effects of effective treatment with EEN in CD.

Assessing disease activity using the pediatric Crohn’s disease activity index: Can we use subjective or objective parameters alone?

BACKGROUND

The pediatric Crohn’s disease activity index (PCDAI) is used as a standard tool to assess disease activity in clinical trials for pediatric Crohn’s disease.

AIM

To examine which items on the PCDAI drive assessment of disease activity, and how subgroups of subjective and objective items reflect change in disease state over time.

METHODS

Selective raw data from three prospectively collected datasets were combined, including 703 children with full PCDAI data at baseline, at 3-mo (Q1, n = 670), and 1-year (Q4, n = 474). Change in individual PCDAI scores from baseline to Q1 and to Q4 were examined using the non-weighted PCDAI.

RESULTS

Abdominal pain, well-being, weight, and stooling had the highest change scores over time. Objective indicators including albumin, abdominal exam, and height velocity followed. Change scores for well-being and abdominal exam did not explain significant variance at Q1 but were significant predictors at Q4 (P < 0.001 and P < 0.05). Subjective and objective subgroups of items predicted less variance (18% and 22%) on total PCDAI scores at Q1 and Q4 compared to the full PCDAI, or a composite scale (both 32%) containing significant predictors.

CONCLUSION

Although subjective items on the PCDAI change the most over time, the full PCDAI or a smaller composite of items including a combination of subjective and objective components classifies disease activity better than a subgroup of either subjective or objective items alone. Reliance on subjective or objective items as stand-alone proxies for disease activity measurement could result in misclassification of disease state.

Nutritional Aspects of Pediatric Gastrointestinal Diseases

In the last decade, the role of nutritional management in pediatric gastrointestinal diseases has gained increasing popularity. Disease-specific diets have been introduced as conventional treatments by international guidelines. Patients tend to more willingly accept food-based therapies than drugs because of their relatively “harmless” nature. Apart from a diet’s therapeutic role, nutritional support is crucial in maintaining growth and improving clinical outcomes in pediatric patients. Despite the absence of classical “side effects”, however, it should be emphasized that any dietary modification might have negative consequences on children’s growth and development. Hence, expert supervision is always advised, in order to support adequate nutritional requirements. Unfortunately, the media provide an inaccurate perception of the role of diet for gastrointestinal diseases, leading to misconceptions by patients or their caregivers that tends to overestimate the beneficial role of diets and underestimate the potential adverse effects. Moreover, not only patients, but also healthcare professionals, have a number of misconceptions about the nutritional benefits of diet modification on gastrointestinal diseases. The aim of this review is to highlight the role of diet in pediatric gastrointestinal diseases, to detect misconceptions and to give a practical guide for physicians on the basis of current scientific evidence.

Current recommendations on the role of diet in the aetiology and management of IBD

Diet is a key modifier of risk of inflammatory bowel disease development and potentially a treatment option in patients with established disease. International organisations in gastroenterology and inflammatory bowel disease have published guidelines for the role of diet in disease onset and its management. Here, we discuss the major overarching themes arising from these guidelines and appraise recent literature on the role of diet for inflammatory bowel disease prevention, treatment of active disease and maintenance of remission, considering these themes. Except for exclusive enteral nutrition in active Crohn's disease, we currently possess very little evidence to make any further dietary recommendations for the management of inflammatory bowel disease. There is also currently uncertainty on the extrapolation of epidemiological dietary signals on risk of disease development and preclinical experiments in animal models to management, once disease is established. Until high-quality evidence from clinical research becomes available, the only specific recommendations for inflammatory bowel disease we might safely give are those of healthy eating which apply for the general population for overall health and well-being.

Dietary Management in Pediatric Patients with Crohn's Disease

It has been widely endorsed that a multifactorial etiology, including interaction between genetic and environmental factors, can contribute to Crohn's Disease (CD) pathogenesis. More specifically, diet has proven to be able to shape gut microbiota composition and thus is suspected to play a significant role in inflammatory bowel disease (IBD) pathogenesis. Moreover, poor nutritional status and growth retardation, arising from several factors such as reduced dietary intake or nutrient leakage from the gastrointestinal tract, represent the hallmarks of pediatric CD. For these reasons, multiple research lines have recently focused on the utilization of dietary therapies for the management of CD, aiming to target concurrently mucosal inflammation, intestinal dysbiosis and optimization of nutritional status. The forerunner of such interventions is represented by exclusive enteral nutrition (EEN), a robustly supported nutritional therapy; however, it is burdened by monotony and low tolerance in the long term. Novel dietary interventions, such as Crohn's Disease Exclusion Diet or Crohn's Disease treatment with eating, have shown their efficacy in the induction of remission in pediatric patients with CD. The aim of the present narrative review is to provide a synopsis of the available nutritional strategies in the management of pediatric CD and to discuss their application in the dietary management of these patients.

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.

The Role of Diet in the Pathogenesis and Management of Inflammatory Bowel Disease: A Review

Inflammatory bowel diseases, which include ulcerative colitis and Crohn’s disease, are chronic relapsing and remitting inflammatory diseases of the gastrointestinal tract that are increasing in prevalence and incidence globally. They are associated with significant morbidity, reduced quality of life to individual sufferers and are an increasing burden on society through direct and indirect costs. Current treatment strategies rely on immunosuppression, which, while effective, is associated with adverse events. Epidemiological evidence suggests that diet impacts the risk of developing IBD and modulates disease activity. Using diet as a therapeutic option is attractive to patients and clinicians alike due to its availability, low cost and few side effects. Diet may influence IBD risk and disease behaviour through several mechanisms. Firstly, some components of the diet influence microbiota structure and function with downstream effects on immune activity. Secondly, dietary components act to alter the structure and permeability of the mucosal barrier, and lastly dietary elements may have direct interactions with components of the immune response. This review will summarise the mechanisms of diet–microbial–immune system interaction, outline key studies examining associations between diet and IBD and evidence demonstrating the impact of diet on disease control. Finally, this review will outline current prescribed dietary therapies for active CD.

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.

Role of Diet in the Development and Management of Crohn's Disease

PURPOSE OF REVIEW

This article provides an updated review on the role of diet in the risk of developing Crohn's disease (CD) and CD management, areas of ongoing study.

RECENT FINDINGS

Higher intake of dietary fiber (fruit fiber) has been associated with a reduced risk for CD. The exclusive enteral nutrition (EEN) diet remains the most validated nutritional recommendation for inducing remission in CD. The specific carbohydrate diet (SCD) has demonstrated reductions in CD severity scores in conjunction with medical therapies, and larger trials on its efficacy are ongoing. Several new exclusion diets modeled after EEN and SCD have shown potential efficacy in smaller studies that warrant replication. There is a paucity of clear dietary recommendations for the reduction in risk of CD clinical relapse. There are various components of diet that likely impact risk for CD development and contribute to its disease course; however, studies are often limited in their size or ability to demonstrate mechanistic causation. Further studies including diets that aim to expand on the restrictive nature of EEN may lead to stronger evidence for a diet-based approach to CD management.

Partial enteral nutrition induces clinical and endoscopic remission in active pediatric Crohn's disease: results of a prospective cohort study

The aim of this study was to evaluate rates of clinical remission, endoscopic remission, and mucosal healing after a 6-week treatment period with partial enteral nutrition (PEN) and to compare them to those obtained by standard exclusive enteral nutrition (EEN) treatment in children with active Crohn's disease (CD). Twenty-five patients with active CD (median age 13.6 years, range 3.6-18.0) were recruited to either PEN (n = 12) or EEN (n = 13) treatment groups. The PEN group received 75% of their dietary needs from a polymeric formula plus one meal per day from an anti-inflammatory diet (AID). Patients were assessed at weeks 0, 1, 3, and 6 using clinical and laboratory parameters. Endoscopic assessment was performed at induction and week 6. On intention to treat analysis, clinical remission (Pediatric CD Activity Index < 10) was achieved in 69.2% and 75.0% of EEN and PEN patients, respectively (p = 0.999). The endoscopic remission (Simple Endoscopic Score for CD (SES-CD) ≤ 2) rates were 45.5% in both groups, while mucosal healing rates (SES-CD = 0) were 45.5% with EEN and 27.3% with PEN (p = 0.659).Conclusion: The results of our prospective pilot study suggest that PEN, allowing one meal from AID, could be as effective as EEN in inducing clinical and endoscopic remission in children with active CD. However, larger randomized controlled studies are warranted to confirm our findings.Trial registration: This clinical trial was registered under the number ClinicalTrials.govidentifier: NCT03176875.What is Known:• Exclusive enteral nutrition is a first-line treatment in active pediatric Crohn's disease; however, patients often find it difficult to adhere to.• Exclusive enteral nutrition is more effective than corticosteroids in achieving mucosal healing.What is New:• This is the first prospective study on partial enteral nutrition in active pediatric Crohn's disease, evaluating not only clinical, but also endoscopic remission.• A novel approach of partial enteral nutrition that allows one meal per day from an anti-inflammatory diet was as effective as exclusive enteral nutrition in inducing clinical and endoscopic remission in active Crohn's disease.