The Importance and Challenges of Dietary Intervention Trials for Inflammatory Bowel Disease

Food-Based Interventions as Therapy for Inflammatory Bowel Disease: Important Steps in Diet Trial Design and Reporting of Outcomes

Diet therapy for inflammatory bowel disease (IBD) is an international research priority but guidance for IBD-specific diet trial design is lacking. This review critically evaluates key elements of prospective IBD food-based intervention trials and identifies gaps. Electronic databases were searched for interventional IBD diet studies. Prospective primary studies/trials were included if used food-based dietary strategies. Forty studies/trials evaluating 29 food-based strategies as therapy for IBD were identified. Considerable heterogeneity in diets, trial design, and methodology exists. Thirty-one trials (78%) intended the diet to modulate inflammation but 14/31 (46%) did not have a primary endpoint measuring an objective change in inflammatory activity and 20/31 (65%) controlled for medication stability prior to application of diet at baseline. Higher-quality IBD diet trials used symptom-based assessment tools coupled with an objective evaluation of inflammatory activity. Dietary advice trials are the most common. One-third of trials developed and administered diet education without a dietitian. Evaluation and reporting on adherence to diet therapy occurred in <60% of trials. Failure to include or report on key elements of trial design reduced the interpretability and validity of the results. This is a considerable limitation to advancing scientific knowledge in this area. Diet therapy trials should adhere to similar rigorous quality standards used to develop other IBD therapies. Therefore, a set of practical recommendations was generated to provide the authors' perspective to help inform the future design of high-quality IBD diet trials.

A Personalized Mediterranean Diet Improves Pain and Quality of Life in Patients with Fibromyalgia

INTRODUCTION

Fibromyalgia is a form of chronic pain that affects a large number of women. It can start at any age and last a lifetime, with no cure. The Mediterranean diet is said to have an anti-inflammatory effect. Therefore, this study was conducted to investigate possible beneficial effects of a personalized Mediterranean diet in patients with fibromyalgia.

METHODS

Outpatients with fibromyalgia were recruited and invited to participate in the study, including clinical, nutritional, and dietary assessments. Patients received a personalized Mediterranean diet (DIET group) or a general balanced diet (NODIET group) to be followed for 8 weeks. All tests were carried out at baseline and repeated after 4 and 8 weeks.

RESULTS

In total, 100 subjects were included, 84 of whom completed the study. Most of the patients showed incorrect habits in terms of food choices, timing of meals and composition of nutrients. The DIET group showed an improvement in most of the fibromyalgia parameters, including the disability scores, fatigue, and anxiety.

CONCLUSIONS

The habit of eating inflammatory foods and/or eating meals with the wrong nutritional content would increase the negative status of patients with fibromyalgia. With this study, we confirm that proper attention to feeding habits would improve the quality of life of such patients.

Dietary Effects on Pain Symptoms in Patients with Fibromyalgia Syndrome: Systematic Review and Future Directions

Fibromyalgia syndrome (FMS) is recognized for its difficulty to diagnose and its subjective symptomatology. There is neither a known cure nor a recommended therapeutic diet to aid in the multidisciplinary treatment. We conducted a systematic review to investigate if diets can improve pain symptoms of fibromyalgia. Through the PubMed search in March 2022, 126 abstracts were identified. We included both intervention and observational studies of diets and pain symptoms among patients with FMS. After screening titles, abstracts, and full-texts, 12 studies, including 11 intervention and one observational study, were selected. These studies included 546 participants and investigated plant-based diets (n = 3), anti-inflammatory diets (n = 1), gluten-free diets (n = 2), and elimination/restrictive diets (n = 6). These studies assessed pain symptoms through visual analogue scale for pain, fibromyalgia impact questionnaire/revised fibromyalgia impact questionnaire, tender point count, pain pressure threshold, and/or total myalgic score. Nine studies, including all three plant-based diet studies, reported statistically significant beneficial effects of their respective diets on pain symptom measurements. Given the small sample size and short intervention duration of the included studies, limited evidence currently exists to recommend any specific diet to patients with FMS. Further research is warranted to clarify specific diets to recommend and explore their potential mechanisms.

Web-based dietary assessment and advice helps inflammatory bowel disease patients to improve their diet quality

Time to evaluate diet quality and give dietary advice is limited in clinical inflammatory bowel disease (IBD) practice. The Eetscore is a web-based tool that assesses diet quality according to the Dutch dietary guidelines and provides personalised dietary advice. We aimed to assess diet quality of IBD patients using the Eetscore and to study changes in diet quality, health-related quality of life (HRQoL) and clinical disease activity over time. A prospective cohort study was performed in 195 adult IBD patients. Participants were invited to fill out questionnaires (Eetscore-FFQ, short Inflammatory Bowel Disease Questionnaire and Patient Harvey Bradshaw Index/Patient Simple Clinical Colitis Activity Index) at baseline and after 1 and 4 months. The Eetscore calculates diet quality based on sixteen food components (ten points per component, total score 0-160; the higher the better) and provides dietary advice per component based on the assessment. At baseline, mean diet quality was 98 (sd 19). Diet quality was positively associated with age, female sex and level of education. Component scores were highest for red meat, wholegrain products and sweetened beverages, and lowest for legumes, nuts and processed meat. Over time, diet quality increased to 107 (sd 21) at 4 months (P < 0·001). Each ten-point improvement in diet quality was associated with an increase in HRQoL (β = 0·4 (95 % CI (0·02, 0·7), P = 0·04). Clinical disease activity did not change. In conclusion, diet quality of IBD patients significantly improved following personalised dietary advice of the Eetscore. Improvement of diet quality was associated with a slight improvement in HRQoL. The Eetscore is a practical and useful tool to monitor and support a healthy diet in IBD patients.

Lower Impact of Disease on Daily Life and Less Fatigue in Patients With Inflammatory Bowel Disease Following a Lifestyle Intervention

BACKGROUND

Despite the potential benefits of diet and physical activity, evidence for beneficial effects of a combined lifestyle intervention is lacking in patients with inflammatory bowel disease (IBD). Therefore, we assessed its effects on impact of disease on daily life, clinical disease activity, fatigue, and health-related quality of life (HRQoL) in patients with IBD.

METHODS

A 6-month single-arm intervention study was performed in adult IBD patients in remission or with mildly active disease. Participants received personal dietary and physical activity advice from a dietician and a physiotherapist in 6 consults. At baseline and over time, questionnaires on diet quality, physical activity, and disease-related outcomes were completed and fecal calprotectin was determined. Data were analyzed by linear mixed models.

RESULTS

During the intervention, diet quality significantly increased (P < .001), but the level of physical activity remained the same. Over time, impact of the disease on daily life reduced (P = .009) and fatigue decreased (P = .001), while clinical disease activity, HRQoL, and fecal calprotectin did not change. Improvement in diet quality was significantly associated with a lower impact of disease on daily life (β = 0.09; 95% confidence interval [CI], 0.03 to 0.15; P = .003) and less fatigue (β = -0.13; 95% CI, -0.20 to -0.07; P < .001) but not with clinical disease activity, HRQoL, and fecal calprotectin. No associations were found with physical activity.

CONCLUSIONS

This combined lifestyle intervention significantly improved diet quality, and this improvement was associated with a reduction in the impact of disease on daily life and fatigue in patients with IBD in remission or with mildly active disease.

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.

Dietary Patterns and Gut Microbiota: The Crucial Actors in Inflammatory Bowel Disease

It is widely believed that diet and the gut microbiota are strongly related to the occurrence and progression of inflammatory bowel disease (IBD), but the effects of the interaction between dietary patterns and the gut microbiota on IBD have not been well elucidated. In this article, we aim to explore the complex relation between dietary patterns, gut microbiota, and IBD. We first comprehensively summarized the dietary patterns associated with IBD and found that dietary patterns can modulate the occurrence and progression of IBD through various signaling pathways, including mammalian target of rapamycin (mTOR), mitogen-activated protein kinases (MAPKs), signal transducer and activator of transcription 3 (STAT3), and NF-κB. Besides, the gut microbiota performs a vital role in the progression of IBD, which can affect the expression of IBD susceptibility genes, such as dual oxidase 2 (DUOX2) and APOA-1 , the intestinal barrier (in particular, the expression of tight junction proteins), immune function (especially the homeostasis between effector and regulatory T cells) and the physiological metabolism, in particular, SCFAs, bile acids (BAs), and tryptophan metabolism. Finally, we reviewed the current knowledge on the interaction between dietary patterns and the gut microbiota in IBD and found that dietary patterns modulate the onset and progression of IBD, which is partly attributed to the regulation of the gut microbiota (especially SCFAs-producing bacteria and Escherichia coli). Faecalibacteria as "microbiomarkers" of IBD could be used as a target for dietary interventions to alleviate IBD. A comprehensive understanding of the interplay between dietary intake, gut microbiota, and IBD will facilitate the development of personalized dietary strategies based on the regulation of the gut microbiota in IBD and expedite the era of precision nutritional interventions for IBD.

Differences in Nutrient Intake with Homemade versus Chef-Prepared Specific Carbohydrate Diet Therapy in Inflammatory Bowel Disease: Insights into Dietary Research

PURPOSE

The aim of this study was to evaluate the nutrient content consumed by children and adolescents on home-prepared versus chef-prepared specific carbohydrate diets (SCD) as therapy for inflammatory bowel disease (IBD).

METHODS

Dietary intake of two cohorts with active IBD initiating the SCD over 12 weeks was assessed. The home-prepared cohort received detailed guidance from dietitians on implementation of the SCD. The chef in the other cohort was knowledgeable in the SCD and prepared meals from a fixed set of recipes. Data from 3-day diet diaries at 4 different time points were collected. US Recommended Daily Allowances (RDA) were calculated for macronutrients, vitamins, and minerals.

RESULTS

Eight participants on the homemade SCD and 5 participants on the chef-prepared SCD were included in analysis. Mean % RDA for energy intake was 115% and 87% for homemade and chef-prepared groups (p<0.01). Mean % RDA for protein intake was 337% for homemade SCD and 216% for chef-prepared SCD (p<0.01). The homemade SCD group had higher mean % RDA values for vitamin A and iron, while the chef-prepared SCD group had higher intake of vitamins B1, B2, D, phosphorus and zinc (p<0.01 for all).

CONCLUSION

The SCD implemented homemade versus chef-prepared can result in significantly different intake of nutrients and this may influence efficacy of this dietary therapy. Meal preparation dynamics and the motivation of families who pursue dietary treatment may play an important role on the foods consumed and the outcomes on dietary therapy with the SCD.

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.

Medical Food Assessment Using a Smartphone App With Continuous Glucose Monitoring Sensors: Proof-of-Concept Study

Background

Novel wearable biosensors, ubiquitous smartphone ownership, and telemedicine are converging to enable new paradigms of clinical research. A new generation of continuous glucose monitoring (CGM) devices provides access to clinical-grade measurement of interstitial glucose levels. Adoption of these sensors has become widespread for the management of type 1 diabetes and is accelerating in type 2 diabetes. In parallel, individuals are adopting health-related smartphone-based apps to monitor and manage care.

Objective

We conducted a proof-of-concept study to investigate the potential of collecting robust, annotated, real-time clinical study measures of glucose levels without clinic visits.

Methods

Self-administered meal-tolerance tests were conducted to assess the impact of a proprietary synbiotic medical food on glucose control in a 6-week, double-blind, placebo-controlled, 2×2 cross-over pilot study (n=6). The primary endpoint was incremental glucose measured using Abbott Freestyle Libre CGM devices associated with a smartphone app that provided a visual diet log.

Results

All subjects completed the study and mastered CGM device usage. Over 40 days, 3000 data points on average per subject were collected across three sensors. No adverse events were recorded, and subjects reported general satisfaction with sensor management, the study product, and the smartphone app, with an average self-reported satisfaction score of 8.25/10. Despite a lack of sufficient power to achieve statistical significance, we demonstrated that we can detect meaningful changes in the postprandial glucose response in real-world settings, pointing to the merits of larger studies in the future.

Conclusions

We have shown that CGM devices can provide a comprehensive picture of glucose control without clinic visits. CGM device usage in conjunction with our custom smartphone app can lower the participation burden for subjects while reducing study costs, and allows for robust integration of multiple valuable data types with glucose levels remotely.

Trial Registration

ClinicalTrials.gov NCT04424888; http://clinicaltrials.gov/ct2/show/NCT04424888.

Impact of diet and the bacterial microbiome on the mucous barrier and immune disorders

The prevalence of chronic immune and metabolic disorders is increasing rapidly. In particular, inflammatory bowel diseases, obesity, diabetes, asthma and chronic obstructive pulmonary disease have become major healthcare and economic burdens worldwide. Recent advances in microbiome research have led to significant discoveries of associative links between alterations in the microbiome and health, as well as these chronic supposedly noncommunicable, immune/metabolic disorders. Importantly, the interplay between diet, microbiome and the mucous barrier in these diseases has gained significant attention. Diet modulates the mucous barrier via alterations in gut microbiota, resulting in either disease onset/exacerbation due to a "poor" diet or protection against disease with a "healthy" diet. In addition, many mucosa-associated disorders possess a specific gut microbiome fingerprint associated with the composition of the mucous barrier, which is further influenced by host-microbiome and inter-microbial interactions, dietary choices, microbe immigration and antimicrobials. Our review focuses on the interactions of diet (macronutrients and micronutrients), gut microbiota and mucous barriers (gastrointestinal and respiratory tract) and their importance in the onset and/or progression of major immune/metabolic disorders. We also highlight the key mechanisms that could be targeted therapeutically to prevent and/or treat these disorders.

Inflammatory bowel disease: tri-directional relationship between microbiota, immune system and intestinal epithelium

Human gut microbiota contributes to host nutrition and metabolism, sustains intestinal cell proliferation and differentiation, and modulates host immune system. The alterations in their composition lead to severe gut disorders, including inflammatory bowel disease (IBD) or inflammatory bowel syndrome (IBS). IBD including ulcerative colitis (UC) and Crohn's disease (CD) are gamut of chronic inflammatory disorders of gut, mediated by complex interrelations among genetic, environmental, and internal factors. IBD has debateable aetiology, however in recent years, exploring the central role of a tri-directional relationship between gut microbiota, mucosal immune system, and intestinal epithelium in pathogenesis is getting the most attention. Increasing incidences and early onset explains the exponential rise in IBD burden on health-care systems. Industrialization, hypersensitivity to allergens, lifestyle, hygiene hypothesis, loss of intestinal worms, and gut microbial composition, explains this shifted rise. Hitherto, the interventions modulating gut microbiota composition, microfluidics-based in vitro gastrointestinal models, non-allergic functional foods, nutraceuticals, and faecal microbiota transplantation (FMT) from healthy donors are some of the futuristic approaches for the disease management.

Diet Recommendations for Hospitalized Patients With Inflammatory Bowel Disease: Better Options Than Nil Per Os

Hospitalizations are a time when providers often have uncertainty about what to feed patients with inflammatory bowel disease (IBD). While there are many trials evaluating the role of diet in the management of IBD, the role of diet for the hospitalized patient is less clear. The hospitalization may serve as an opportunity to educate patients about the role of diet, try different diets, and develop dietary recommendations for after discharge. Here, we review the literature for dietary considerations during hospitalizations and acute settings, as well as upon discharge. Patients with IBD benefit from screening and nutritional support for malnutrition and nutritional deficiencies. Enteral nutrition and exclusion diets are promising as induction and maintenance therapies, but no specific recommendations during hospitalization for adult patients are available currently. There are very few reasons to enforce bowel rest or clear liquids other than bowel obstruction, uncontrolled sepsis, or need for urgent or emergent surgery; most patients - including many with penetrating or stricturing disease - benefit from feeding in whichever capacity is tolerated, with enteral and parenteral nutrition used as needed to reach nutritional goals. Future studies are needed to define how the use of different diets can influence the outcomes of patients hospitalized for IBD.

The relationship between inflammatory bowel disease and Helicobacter pylori across East Asian, European and Mediterranean countries: a meta-analysis

Background

The current literature suggests a protective benefit of Helicobacter pylori (H. pylori) infection against inflammatory bowel disease (IBD). Here we assessed whether this effect varied by IBD subtype—Crohn’s disease (CD) or ulcerative colitis (UC)—and geographic region: East Asia, Europe (non-Mediterranean) or Mediterranean region.

Methods

A database search was performed up to July 2019 inclusive for all studies that compared H. pylori infection in IBD patients vs. non-IBD controls. The relative risk (RR) was used to quantify the association between IBD and H. pylori, and the effects were combined across studies using a mixed-effects meta-regression model, which included IBD subtype and geographic region as categorical moderator variables.

Results

Our meta-regression model exhibited moderate heterogeneity (I²=48.74%). Pooled RR depended on both region (P=0.02) and subtype (P<0.001). Pooled RRs were <1 for all subtype and region combinations, indicative of a protective effect of H. pylori against IBD. The pooled RR was 28% (9%, 50%; P=0.001) greater for UC vs. CD and 43% (4%, 96%; P=0.02) greater for Mediterranean countries vs. East Asia. The pooled RR was 18% (-13%, 60%; P=0.48) greater for Europe vs. East Asia and 21% (-13%, 68%; P=0.42) greater for Mediterranean vs. Europe, though these differences were not statistically significant.

Conclusions

The protective effect of H. pylori on IBD varied by both subtype (more protection against CD vs. UC) and region (East Asia more protected than Mediterranean regions). Variation due to these effects could provide insight into IBD etiology.

Dietary Guidance From the International Organization for the Study of Inflammatory Bowel Diseases

Recent evidence points to a plausible role of diet and the microbiome in the pathogenesis of both Crohn's disease (CD) and Ulcerative Colitis (UC). Dietary therapies based on exclusion of table foods and replacement with nutritional formulas and/or a combination of nutritional formulas and specific table foods may induce remission in CD. In UC, specific dietary components have also been associated with flare of disease. While evidence of varying quality has identified potential harmful or beneficial dietary components, physicians and patients at the present time do not have guidance as to which foods are safe, may be protective or deleterious for these diseases. The current document has been compiled by the nutrition cluster of the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) based on the best current evidence to provide expert opinion regarding specific dietary components, food groups and food additives that may be prudent to increase or decrease in the diet of patients with inflammatory bowel diseases to control and prevent relapse of inflammatory bowel diseases.

Diet Therapy for Inflammatory Bowel Diseases: A Call to the Dining Table

There is vigorous interest among patients, caregivers, clinicians, and scientists to identify useful dietary interventions for inflammatory bowel diseases (IBD). Through the Cochrane Collaboration, we recently performed a systematic review and meta-analysis of dietary interventions for the induction or maintenance of remission in Crohn's disease (CD) and ulcerative colitis (UC) to assess the latest state of research. The current quality of evidence was formally graded to be low or very low for various methodological reasons, such as small sample sizes, heterogeneity among studies, and incomplete reporting. There are nonetheless emerging observational studies that progressively advance our knowledge and provide hope for a role of diet among traditional therapies to improve inflammation and symptoms. Further investments and concerted efforts in research are needed to significantly move the needle in identifying effective dietary therapies for IBD.

Pursuing Human-Relevant Gut Microbiota-Immune Interactions

The gut microbiota is a complex and plastic network of diverse organisms intricately connected with human physiology. Recent advances in profiling approaches of both the microbiota and the immune system now enable a deeper exploration of immunity-microbiota connections. An important next step is to elucidate a human-relevant "map" of microbial-immune wiring while focusing on animal studies to probe a prioritized subset of interactions. Here, we provide an overview of this field's current status and discuss two approaches for establishing priorities for detailed investigation: (1) longitudinal intervention studies in humans probing the dynamics of both the microbiota and the immune system and (2) the study of traditional populations to assess lost features of human microbial identity whose absence may be contributing to the rise of immunological disorders. These human-centered approaches offer a judicious path forward to understand the impact of the microbiota in immune development and function.

Importance of nutritional therapy in the management of intestinal diseases: beyond energy and nutrient supply

The gut is an immune-microbiome-epithelial complex. Gut microbiome-host interactions have widespread biological implications, and the role of this complex system extends beyond the digestion of food and nutrient absorption. Dietary nutrients can affect this complex and play a key role in determining gut homeostasis to maintain host health. In this article, we review various dietary nutrients and their contribution to the pathogenesis and treatment of various intestinal diseases including inflammatory bowel disease, irritable bowel syndrome, colorectal cancer, and diverticulitis, among other such disorders. A better understanding of diet-host-gut microbiome interactions is essential to provide beneficial nutrients for gut health and to limit nutritional hazards to ensure successful nutritional management of gastrointestinal conditions in clinical practice.

An Autoimmune Protocol Diet Improves Patient-Reported Quality of Life in Inflammatory Bowel Disease

BACKGROUND

Prior studies suggest dietary modification may improve clinical response or remission rates in patients with inflammatory bowel disease (IBD). Our aim was to examine whether an autoimmune protocol diet improves quality of life in patients with active Crohn disease (CD) and ulcerative colitis (UC).

METHODS

We conducted an uncontrolled clinical trial of the autoimmune protocol diet in adult patients with active IBD (Harvey-Bradshaw Index ≥ 5 for CD or partial Mayo score ≥ 3 for UC, and erosions/ulcers on endoscopy and/or elevated fecal calprotectin). The dietary intervention consisted of a 6-week elimination phase, followed by a 5-week maintenance phase. Short Inflammatory Bowel Disease Questionnaire (SIBDQ) was completed at baseline, and weeks 3, 6, 9, and 11.

RESULTS

The final cohort included 6 UC and 9 CD participants. Mean SIBDQ score improved significantly from baseline (46.5) to weeks 3 (54.0, P = 0.02), 6 (53.3, P = 0.02), 9 (62.0, P = 0.03), and 11 (60.5, P = 0.05). Among participants completing all 5 surveys, mean SIBDQ increased from 46.5 to 61.5 by week 11 (P = 0.03). By week 3, participants experienced significant improvements in bowel movement frequency (36%, P = 0.04), stress (28%, P = 0.01), and ability to perform leisure/sport activities (29%, P = 0.02). Effects were not significantly different between CD and UC participants.

CONCLUSIONS

Dietary modification can improve quality of life as early as week 3 in patients with active IBD. Larger randomized controlled trials are needed to examine dietary interventions in IBD.

Dietary Management of Pediatric Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, is a life-long relapsing and remitting condition characterized by inflammation of the intestine. While the exact pathogenesis of IBD is unclear, the current belief is that both genetic and environmental factors play a role in development of disease. Management options include nutritional, pharmacological, and surgical therapies. In particular, nutritional therapies for IBD have garnered significant interest due to their limited side effect profile, bowel-sparing nature, and naturalistic approach. This review will examine the role of diet in the pathogenesis and malnutrition in IBD, and will discuss dietary approaches to management of IBD, including exclusive enteral nutrition, specific carbohydrate diet, anti-inflammatory diet, and food supplements (specifically curcumin and long-chain n-3 polyunsaturated fatty acids). Past and recent literature on these subjects were reviewed in Medhub and Scopus databases for this review article with a focus on pediatric and high-quality publications. At this time, these approaches seem to be safe and show promise of an efficacious sole or supplemental role in the treatment of IBD, but randomized, prospective studies are lacking. Additional studies investigating these diets and food supplements are needed to provide more information on their efficacy, mechanism, applicability, and safety.

A Diet Low in Red and Processed Meat Does Not Reduce Rate of Crohn's Disease Flares

BACKGROUND & AIMS

Diet may be an important factor in the progression of Crohn's disease (CD). We performed a randomized controlled trial to determine whether reduced consumption of red and processed meats decreases the risk of symptomatic relapse of CD, analyzing results from the Food and Crohn's Disease Exacerbation Study (FACES) trial.

METHODS

Adults with CD were recruited into the FACES trial from IBD Partners, an Internet-based cohort of patients with inflammatory bowel disease, from November 2013 through June 2015. Individuals who were in remission (CD activity index [sCDAI] scores of ≤150), had completed a biannual survey, and reported consumption of red meat at least once weekly were randomly assigned to groups that consumed a minimum of 2 servings/week of red or processed meat (high meat, n = 118) or not more than 1 serving per month (low meat, n = 96) for 49 weeks. The primary outcome was relapse of CD, defined as increase in sCDAI score by ≥70 points and to >150 or a need for CD surgery or new CD medication. A secondary outcome, moderate or severe relapse, was based on an increase in sCDAI to >219.

RESULTS

During the trial, the high-meat groups reported consumption of 2 or more servings of red or processed meat during 98.5% of observed weeks compared with 18.8% of weeks for the low-meat group. Any and moderate to severe relapse occurred in 62% of participants in the high-meat group and 42% of participants in the low-meat group. There were no significant differences in time to any (P = .61) or moderate/severe (P = .50) relapse.

CONCLUSIONS

In an analysis of data from the FACES trial, we found that among patients with CD in remission, level of red and processed meat consumption was not associated with time to symptomatic relapse. ClinicalTrials.gov, Number: NCT0192673.

Pomegranate juice to reduce fecal calprotectin levels in inflammatory bowel disease patients with a high risk of clinical relapse: Study protocol for a randomized controlled trial

Background

Inflammatory bowel disease (IBD) is a chronic condition characterized by recurrent episodes of intestinal inflammation and is thought to be related to an autoimmune reaction to genetic and environmental factors. Although evidence indicates that a polyphenolic-rich diet plays an important role in modulating aspects of chronic inflammation, few studies have focused on the effect of ellagitannin (ET)-rich food consumption on long-term remission maintenance in IBD patients with a high risk of clinical relapse. Therefore, we hypothesize that supplementation with a pomegranate juice, a naturally rich source of ETs, could significantly modulate the markers of mucosal and systemic inflammation relative to a control group receiving a placebo.

Methods/design

This double-blind, randomized controlled trial includes patients with IBD involving the colorectum who have been in stable therapy for at least the three previous months and have a high risk of clinical relapse. Participants are randomly allocated to one of two groups: active supplementation (125 mL of cv. Wonderful pomegranate juice) or placebo (125 mL) taken twice daily for 12 weeks. The primary outcome is changes in the fecal neutrophil-derived protein calprotectin, a surrogate marker of mucosal improvement, between the two groups from baseline to 12 weeks later. The secondary outcomes include transcriptomic changes in peripheral blood mononuclear cells and intestinal biopsies and changes in circulating inflammatory markers and trimethylamine-N-oxide levels. Pomegranate ET-derived metabolites are identified and quantified in plasma and urine samples.

Discussion

The results will provide information on the possible reduction of fecal calprotectin levels following the consumption of pomegranate juice. The findings will also show the in vivo metabolism of pomegranate ETs. Finally, the effect of 12-week pomegranate juice consumption on local and systemic inflammatory markers will be elucidated, which will likely provide additional insights into the maintenance of remission in IBD patients.

Trial registration

ClinicalTrials.gov, NCT03000101. Registered on 21 December 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3321-8) contains supplementary material, which is available to authorized users.

A Review of Dietary Therapy for IBD and a Vision for the Future

Inflammatory bowel disease (IBD) is a chronic inflammatory condition affecting the gastrointestinal tract. The rising incidence of IBD has been associated with urbanization and shifts toward a Westernized diet. The intestinal microbiome has been a focus of disease pathogenesis and also therapeutic intervention. Dietary therapy for IBD has been well-studied with exclusive enteral nutrition, a formula-based diet with the exclusion of foods. In addition, interest in food-based exclusion diets has been increasing, with patients and families leading the charge. Challenges with dietary therapy for IBD include the lack of understanding of a detailed mechanistic pathway to explain the impact of diet on IBD pathogenesis and the difficult nature of designing and implementing dietary clinical trials. Epidemiological studies have demonstrated associations and intervention studies have demonstrated efficacy, but specific dietary targets remain as hypotheses at present. Current IBD therapy focuses on suppression of the immune system, yet the incomplete efficacy of present drugs suggests that other therapies must be developed and employed. Dietary interventions, with known ability to modulate the intestinal microbiome, are a unique opportunity to improve outcomes in IBD. Dietary intervention trials are challenging, and capturing both broad dietary patterns as well as exposure to individual food compounds is important. With increasing patient interest and preliminary research in dietary therapy indicating efficacy, it is imperative to further advance the science of utilizing diet in IBD, as well as to support patients by proactively addressing diet within their care plan.

The Role of Diet in Inflammatory Bowel Disease

PURPOSE OF REVIEW

Diet may play both a causal and therapeutic role for inflammatory bowel disease (IBD). Physicians caring for patients with IBD are often asked to make dietary recommendations. However, there are no well-established guidelines on the use of diet as a treatment of IBD. In this review, we describe the evidence supporting diet as a potential cause for IBD, patient-perceived symptoms based on diet, current research on various diets as a treatment for IBD, and areas of future research.

RECENT FINDINGS

New studies in murine models suggest that dietary emulsifiers may trigger the gut inflammatory cascade. New studies of restriction diets in patients have shown a relationship between dietary intake, symptoms, and bowel inflammation. Until several ongoing clinical trials are completed, a reasonable approach to dietary recommendations for patients with IBD is to propose a well-balanced, healthy (low-fat, low-sugar) diet prepared from fresh ingredients, such as the Mediterranean diet, with exclusions of self-identified foods that worsen or trigger IBD-related symptoms.