A Randomized Trial Comparing the Specific Carbohydrate Diet to a Mediterranean Diet in Adults With Crohn's Disease

Gut microbiota in regulatory T cell generation and function: mechanisms and health implications

The establishment and maintenance of immune homeostasis rely on a dynamic, bidirectional exchange of information between commensal microorganisms and the host immune system. At the center of this process are CD4+Foxp3+ regulatory T cells (Tregs), which have emerged as pivotal mediators to ensure immunological equilibrium. This review explores the sophisticated mechanisms by which the gut microbiota modulates the differentiation, expansion, and functional specialization of Tregs, orchestrating intestinal immune tolerance to support host-microbiota mutualism. We discuss the role of microbial-derived structural components and metabolites in shaping the immunoregulatory fitness of Tregs. Additionally, we explore the impact of gut microbial dysbiosis, where disrupted microbial-immune crosstalk compromises immune tolerance, contributing to the development of inflammatory and autoimmune disorders. Finally, we highlight the potential of microbiota-based strategies to recalibrate intestinal immunity and restore immune tolerance.

Synergistic Benefits of Dietary Strategies in the Management of IBD

PURPOSE OF REVIEW

Inflammatory bowel disease (IBD) patients commonly inquire about the role of diet in the onset and management of their disease process. This review sought to assess the impact of the inflammatory bowel diseases on the nutritional state of patients and evaluate the evidence supporting nutritional interventions as therapy.

RECENT FINDINGS

The role of nutrition has evolved from one of deficient nutrient and calorie replacement alone into a proactive therapeutic for treating active inflammatory disease symptoms. The realization that initiating total parenteral nutrition (TPN) in place of oral take could improve disease symptoms provided the first indication that food intake played a causative role in the IBD. The evolution of TPN to enteral nutrition improved tolerance and reduced side effects but clouded the role of oral intake in the pathophysiology of IBD. Advanced understanding of the role of the microbiota in IBD combined with recognition of the influence of nutrients on microbial composition have ushered in a new era of food as therapy. The role of nutrition in IBD has evolved significantly over the past 30-40 years. From complete elimination of oral intake to the carefully curated menu intended to mold the intestinal microbiota to a non-inflammatory milieu has revolutionized the approach to dietary intervention. Additional studies are warranted to optimize dietary intervention strategies.

Understanding Role of Nutrition in Inflammatory Bowel Disease: A Comprehensive Review With Incorporation of AGA Update

This comprehensive review delves into the evolving landscape of nutrition's role in Inflammatory Bowel Disease (IBD), while incorporating transformative insights from the recently published American Gastroenterology Association (AGA) clinical practice update (CPU) on diet in IBD. Recent years have witnessed a paradigm shift, recognizing diet not only as an influencer in disease development but also as a disease-modifying factor and treatment avenue for IBD. The AGA CPU endorses a balanced Mediterranean-style diet, emphasizing the need for personalized recommendations tailored to individual patient characteristics, including disease course, surgical history, and pharmacotherapy. The implementation of complex nutritional strategies necessitates the involvement of both gastroenterologists and registered dietitians. Guidance for patients and caregivers is available through organizations such as Crohn's and Colitis Canada and Crohn's and Colitis Foundation. While animal models offer valuable insights, the review underscores their limitations in replicating the complexity of IBD biology observed in humans. It advocates for an exploration of nutrigenomics, utilizing molecular tools to analyze how diet-derived bioactive compounds influence gene expression for precision nutrition insights. Practical challenges in dietary intervention studies, including regional variations and complexities in food handling, require attention for enhanced comparability. Limited data exist on combined dietary and medical therapies, but promising outcomes suggest potential synergies. Precision treatments could develop through an understanding of the function of particular food metabolites in influencing inflammation. The objective of this review is to offer a summary of the present comprehension of diet, serving as both a potential factor contributing to and a therapeutic avenue for IBD. Clinical Trial Registration: This study is not a part of a clinical trial.

The use of the Crohn's disease exclusion diet (CDED) in adults with Crohn's disease: A randomized controlled trial

BACKGROUND

The Crohn's disease exclusion diet (CDED) has been shown to induce remission in adult Crohn's disease (CD) patients. The aim of the study is to provide additional evidence-based validation.

METHODS

We conducted an open-label, randomized trial on adult CD patients with mild-to-moderate symptoms to assess CDED efficacy in inducing symptomatic remission using Mediterranean diet as control. We evaluate demographic data, body mass index (BMI), Harvey-Bradshaw Index (HBI), faecal calprotectin, and serum inflammatory indices at baseline, 12, and 24 weeks. Bioelectrical impedance analysis (BIA) was used to ensure the safety of the CDED group every 12 weeks.

RESULTS

Twenty-four patients were assigned to CDED, and 21 to controls, with no baseline differences among the parameters considered. Five CDED patients dropped out due to intolerance within the first 6 weeks. At 12 weeks, CDED patients showed significantly lower HBI and higher remission rates than controls. By 24 weeks, remission rates increased (70.8% vs. 38.1% at 12 weeks and 79.2% vs. 42.9% at 24 weeks; p = .027 and p < .0001, respectively), with significantly lower fibrinogen levels in the CDED group. The administration of CDED was associated with a significant decrease in BMI (25.8 kg/m2-24.5 kg/m2, p = .047), although BIA analysis showed a decrease in fat mass (18.2%-15.5%, p < .0001), while fat-free mass and body cellular mass significantly increased at 12 weeks (p = .001 and p = .042, respectively) and remained stable at 24 weeks.

CONCLUSIONS

The CDED was effective in inducing remission among patients with mild-to-moderate CD and appeared to be safe and well-accepted.

Beyond Random Fecal Microbial Transplants: Next Generation Personalized Approaches to Normalize Dysbiotic Microbiota for Treating IBD

This review and commentary outline the strong rationale for normalizing the abnormal microbiota of patients with ulcerative colitis, Crohn's disease, and pouchitis and focus on strategies to improve current variable outcomes of fecal microbial transplant (FMT) in ulcerative colitis. Applying lessons from successful FMT therapy of recurrent Clostridioides difficile and insights from basic scientific understanding of host/microbial interactions provide strategies to enhance clinical outcomes in IBD. We outline promising approaches to develop novel-defined consortia of live biotherapeutic products and combination treatments to improve current results and to optimize and personalize treatment approaches in individual patients and disease subsets.

Management of inflammatory bowel disease: a holistic approach beyond pharmacotherapy

INTRODUCTION

Inflammatory bowel diseases (IBD) management extends beyond pharmacotherapy, incorporating psychosocial support, patient education, physical activity, and dietary strategies. These components are often overlooked despite their impact on quality of life (QoL) and treatment adherence. This review explores the role of non-pharmacological strategies in optimizing IBD care.

AREAS COVERED

This article examines the significance of patient-physician communication, disease-specific education, mental health support, exercise, and diet in IBD management. A strong patient-physician relationship fosters trust and adherence to treatment. Knowledge empowers patients, improving long-term control. Psychosocial challenges, including anxiety, depression, and fatigue, further complicate disease management, highlighting the need for timely interventions. Physical activity and dietary interventions play essential roles in reducing sarcopenia and malnutrition, though standardized guidelines are lacking. Literature was reviewed to assess their effectiveness and clinical integration.

EXPERT OPINION

Holistic, multidisciplinary care should be standard in IBD management. Education, mental health screening, and structured diet and exercise plans must be integrated into routine care. Medical training should emphasize communication skills and patient-centered strategies. Future research should establish evidence-based guidelines for implementing these approaches effectively, ensuring improved long-term outcomes for IBD patients.

Gut Feelings: How Microbes, Diet, and Host Immunity Shape Disease

The human gut microbiome is intricately linked to systemic and organ-specific immune responses and is highly responsive to dietary modulation. As metagenomic techniques enable in-depth study of an ever-growing number of gut microbial species, it has become increasingly feasible to decipher the specific functions of the gut microbiome and how they may be modulated by diet. Diet exerts both supportive and selective pressures on the gut microbiome by regulating a multitude of factors, including energy density, macronutrient and micronutrient content, and circadian rhythm. The microbiome, in turn, contributes to local and systemic immune responses by providing colonization resistance against pathogens, shaping immune cell activity and differentiation, and facilitating the production of bioactive metabolites. Emerging research has strengthened the connections between the gut microbiome and cardiometabolic disorders (e.g., cardiovascular disease, obesity, type-2 diabetes), autoimmune conditions (e.g., type-1 diabetes, rheumatoid arthritis, celiac disease), respiratory disease, chronic kidney and liver disease, inflammatory bowel disease, and neurological disorders (e.g., Alzheimer's, Parkinson's disease, depressive disorders). Here, we outline ways in which dietary factors impact host response in diseases through alterations of gut microbiome functionality and composition. Consideration of diet-mediated microbial effects within the context of the diseases discussed highlights the potential of microbiome-targeted treatment strategies as alternative or adjunct therapies to improve patient outcomes.

Dietary Interventions and Oral Nutritional Supplementation in Inflammatory Bowel Disease: Current Evidence and Future Directions

BACKGROUND

Nutritional management has become an integral part of Inflammatory Bowel Disease (IBD) care, with growing evidence supporting specific dietary interventions alongside pharmacologic therapy. However, clinical guidance remains fragmented due to heterogeneous study designs and variable endpoints.

OBJECTIVES

This review critically examines the current evidence on dietary strategies and oral nutritional supplementation (ONS) in both Crohn's Disease (CD) and Ulcerative Colitis (UC), highlighting their clinical applications, mechanisms of action, and limitations.

METHODS

A comprehensive literature search was conducted using PubMed, Scopus, and Web of Science databases, analyzing studies on various dietary approaches and ONS in IBD.

RESULTS

Exclusive Enteral Nutrition (EEN) is a first-line therapy in pediatric CD, while partial enteral nutrition (PEN) and the Crohn's Disease Exclusion Diet (CDED) show promising efficacy and better adherence in both children and adults. Whole-food-based interventions, including the Mediterranean Diet, Specific Carbohydrate Diet, plant-based diets, and emerging strategies such as CD-TREAT and the Tasty & Healthy diet, have demonstrated varying levels of benefit in disease maintenance and symptom control. Targeted exclusion diets-such as low-FODMAP, low-emulsifier, and low-sulfur diets-may relieve functional symptoms and influence inflammatory activity, although evidence remains preliminary. ONS plays a pivotal role in addressing malnutrition and improving outcomes in perioperative and hospitalized patients.

CONCLUSIONS

Dietary interventions and ONS represent valuable therapeutic tools in IBD management. Future research should prioritize standardized, well-powered clinical trials and personalized nutritional approaches to better define their role within integrated care pathways.

Practical Application of Evidence-Based Dietary Therapy in Inflammatory Bowel Disease: The DELECTABLE Program

BACKGROUND/OBJECTIVES

Exclusive Enteral Nutrition (EEN) and the Crohn's Disease Exclusion Diet (CDED) have been shown to induce remission in Crohn's disease. Low-sulphur, plant-based diets are being explored for ulcerative colitis, and wholefood, low-additive approaches are emerging as significant. Although Inflammatory Bowel Disease (IBD) patients modify their diet, evidence for tolerability and benefit outside clinical trials is limited. The DELECTABLE program aimed to assess satisfaction, adherence, and efficacy of dietary therapies as part of IBD care.

METHODS

In this dietitian-led, open-label, prospective study, patients with Crohn's disease were offered the CDED or a whole-food, additive-free diet (WFD), and patients with ulcerative colitis were offered a low-sulphur, plant-based diet (UCD) or WFD. Primary outcomes were 12-week diet satisfaction (modified DSAT-28) and diet adherence, including food additive intake. Secondary outcomes were quality of life (QoL) (IBDQ-9), disease activity (CDAI for Crohn's disease, partial Mayo score for ulcerative colitis), and biochemical markers (CRP, faecal calprotectin). Analyses were conducted within, rather than between, diet arms due to the non-random nature of the study. Diet adherence and disease activity change across time points (baseline, week 6, week 12) were assessed using repeated measures ANOVA or Friedman's test, with pairwise paired t-test or Wilcoxon Signed-Rank test. Diet satisfaction and quality of life changes across time (baseline/week 1, week 12) were assessed using a paired t-test or Wilcoxon Signed-Rank test.

RESULTS

Of 165 referrals, 76 patients enrolled, with 64 completing the 12-week program (CDED: n = 15, WFD: n = 42, UCD: n = 7). Diet satisfaction was initially high and remained stable over time on CDED (p = 0.212) and improved on WFD (p = 0.03). Patient- and dietitian-rated adherence was high at baseline and did not significantly decrease on any diet arm (p > 0.349). Food additive intake decreased on WFD (p = 0.009). QoL improved on CDED and WFD (p < 0.001). CRP, calprotectin, and CDAI were reduced on CDED (p < 0.045), and CDAI and partial Mayo were reduced on WFD (p < 0.027).

CONCLUSIONS

Well-balanced therapeutic diets are feasible and well-accepted by patients with IBD, with a promising impact on disease activity.

Mechanistic Implications of the Mediterranean Diet in Patients With Newly Diagnosed Crohn's Disease: Multiomic Results From a Prospective Cohort

BACKGROUND & AIMS

To decipher the mechanisms underlying the protective role of the Mediterranean diet (MED) in Crohn's disease (CD), we explored the implications of adherence to MED on CD course, inflammatory markers, and microbial and metabolite composition.

METHODS

Patients with newly diagnosed CD were recruited and followed prospectively. MED adherence was assessed by repeated food frequency questionnaires (FFQs) using a predefined inflammatory bowel disease Mediterranean diet score (IBDMED score), alongside validated MED adherence screeners. Crohn's disease activity index (CDAI), C-reactive protein, fecal calprotectin, and microbial composition (16S-ribosomal RNA sequencing) were assessed each visit. Baseline serum and fecal samples were analyzed for targeted quantitative metabolomics.

RESULTS

Consecutive patients: 271 (52% men, average age 31 ± 12 years, B1 phenotype 75%). FFQs collected: 636 (range 1-5 FFQs per patient). Adherence to MED was associated with a noncomplicated CD course, and inversely correlated with CDAI, fecal calprotectin, C-reactive protein, and microbial dysbiosis index (all P < .05). Increasing adherence to MED over time correlated with reduced CDAI and inflammatory markers (P < .05). Adherence to MED correlated with a microbial cluster of commensals and short-chain fatty acid producers including Faecalibacterium, and with plant metabolites, vitamin derivatives, and amino acids. Conversely, adherence to MED inversely correlated with a cluster of oral genera, Escherichia coli and Ruminococcus gnavus, known CD-associated species, and with tryptophan metabolites, ceramides, and primary bile acids (false discovery rate < 0.2).

CONCLUSION

Adherence to MED is associated with beneficial clinical outcomes and decreased inflammatory markers. These may be driven by lower levels of primary bile acids and microbial dysbiosis and a beneficial microbial and metabolite composition. Randomized controlled trials are needed to evaluate the role of MED in CD management.

Sesquiterpene Lactone Lactucopicrin Boosts Apoptotic Cell Clearance by Colonic Epithelial Cells and Alleviates Colitis in Mice

Boosting apoptotic cell clearance by phagocytes including colonic epithelial cells (CECs), a process named efferocytosis, inhibits colitis development. Lactucopicrin (LCP), one common bitter sesquiterpene lactone affluent in leafy vegetables possesses a significant antiinflammatory property. However, it remains unknown whether LCP could regulate CECs efferocytosis and colitis development in vivo. Methods and Results: LCP (0.25-1 µmol/L) does not appreciably change the efferocytic capacity of murine primary CECs to clear apoptotic CECs. Instead, LCP dose-dependently increases the efferocytic capacity of CECs treated with butyrate (But). This effect is reliant on efferocytic receptor brain-specific angiogenesis 1 (BAI1). Although LCP does not significantly affect BAI1 expression, it alters BAI1 distribution with an increase in lipid raft microdomains in plasma membrane, an effect responsible for the LCP effect on efferocytic capacity. Moreover, dietary supplementation with 0.012% wt/wt of LCP attenuates dextran sulfate sodium (DSS)-induced colitis in C57BL/6J mice, along with an increase in efferocytic capacity of CECs and fecal But content, a reduction in apoptotic cell accumulation and inflammation burden in colonic tissues. Conclusion: Dietary LCP could inhibit DSS-induced colitis in mice, likely through enhancing BAI1-mediated efferocytosis of CECs, thus providing a new candidate for the treatment of colitis.

Diet-microbiome interactions in cancer

Diet impacts cancer in diverse manners. Multiple nutritional effects on tumors are mediated by dietary modulation of commensals, residing in mucosal surfaces and possibly also within the tumor microenvironment. Mechanistically understanding such diet-microbiome-host interactions may enable to develop precision nutritional interventions impacting cancer development, dissemination, and treatment responses. However, data-driven nutritional strategies integrating diet-microbiome interactions are infrequently incorporated into cancer prevention and treatment schemes. Herein, we discuss how dietary composition affects cancer-related processes through alterations exerted by specific nutrients and complex foods on the microbiome. We highlight how dietary timing, including time-restricted feeding, impacts microbial function in modulating cancer and its therapy. We review existing and experimental nutritional approaches aimed at enhancing microbiome-mediated cancer treatment responsiveness while minimizing adverse effects, and address challenges and prospects in integrating diet-microbiome interactions into precision oncology. Collectively, mechanistically understanding diet-microbiome-host interactomes may enable to achieve a personalized and microbiome-informed optimization of nutritional cancer interventions.

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.

Quality management of a multi-center randomized controlled feeding trial: A prospective observational study

BackgroundNutrition and dietary trials are often prone to bias, leading to inaccurate or questionable estimates of intervention efficacy. However, reports on quality management practices of well-controlled dietary trials are scarce. This study aims to introduce the quality management system of the Diet, ExerCIse and CarDiovascular hEalth-Diet Study and report its performance in ensuring study quality.MethodsThe quality management system consisted of a study coordinating center, trial governance, and quality control measures covering study design, conduct, and data analysis and reporting. Metrics for evaluating the performance of the system were collected throughout the whole trial development and conducted from September 2016 to June 2021, covering major activities at the coordinating center, study sites, and central laboratories, with a focus on the protocol amendments, protocol deviations (eligibility, fidelity, confounders management, loss to follow-up and outside-of-window visits, and blindness success), and measurement accuracy.ResultsThree amendments to the study protocol enhanced feasibility. All participants (265) met the eligibility criteria. Among them, only 3% were lost to the primary outcome follow-up measurement. More than 95% of participants completed the study, they consumed more than 96% of the study meals, and more than 94% of participants consumed more than 18 meals per week, with no between-group differences. Online monitoring of nutrient targets for the intervention diet showed that all targets were achieved except for the fiber intake, which was 4.3 g less on average. Only 3% experienced a body weight change greater than 2.0 kg, and 3% had medication changes which were not allowed by the study. James' blinding index at the end of the study was 0.68. The end digits of both systolic and diastolic blood pressure readings were distributed equally. For laboratory measures, 100% of standard samples, 97% of blood-split samples, and 87% of urine-split samples had test results within the acceptable range. Only 1.4% of data items required queries, for which only 30% needed corrections.DiscussionThe Diet, ExerCIse and CarDiovascular hEalth-Diet Study quality management system provides a framework for conducting a high-quality dietary intervention clinical trial.

Carbohydrate consumption drives adaptive mutations in Escherichia coli associated with increased risk for systemic infection

Dissemination of organisms from the gut microbiota is a major contributor to sepsis and critical illness. Patients with cirrhosis are prone to systemic infections and are commonly prescribed the carbohydrate lactulose to manage hepatic encephalopathy (HE) 1 . Commensal metabolism of lactulose is believed to reduce pathobiont colonization through short-chain fatty acid production, but its direct effects on gut pathobionts remain unexplored 2 . Here, we show that lactulose consumption unexpectedly selects for mutations in Escherichia coli lactose (lac) operon regulation, enhancing its metabolic fitness and colonization capacity. This is mediated by selection for constitutive expression of the lac operon through mutations in its regulatory components. Using in vitro systems, murine models, and clinical samples, we demonstrate that these mutations enable E. coli to exploit lactulose as a carbon source, bypassing host carbohydrate metabolism and increasing its intestinal colonization. Despite its long-standing use in HE treatment, we find that lactulose has a paradoxical association with risk of infection hospitalization in patients with cirrhosis in a large epidemiologic study. The emergence of lactulose-adapted E. coli strains could be suppressed by a dietary oligosaccharide that competitively inhibits lactulose uptake. These findings reveal a mechanism by which dietary substrates exert selective pressure on the microbiome, with implications for diet-based strategies to modulate microbial evolution and infection risk.

Dietary Nut and Legume Intake and Risk of Crohn's Disease and Ulcerative Colitis

BACKGROUND

We investigated the relationship between nut and legume intake and risk of Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

We conducted a prospective cohort study of 223 283 adults from the Nurses' Health Study (NHS), NHSII, and Health Professionals Follow-Up Study (1986-2017), excluding those with inflammatory bowel disease (IBD) at baseline. Food frequency questionnaires were used to calculate nut and legume intake. Inflammatory bowel disease was self-reported on questionnaires and confirmed via blinded record review. Using Cox proportional hazards models, we calculated adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for CD and UC according to categories of nut and legume intake.

RESULTS

In over 5 460 315 person-years of follow-up (CD = 371, UC = 481), neither nut nor legume intake was associated with CD or UC risk. Compared to those who never consumed nuts, those who consumed nuts ≥2 times/week had an aHR = 0.96 (95% CI, 0.63-1.47; Ptrend = 0.57) for CD and 1.30 (95% CI, 0.92-1.84; Ptrend = 0.36) for UC. Compared to those who consumed legumes 0-3 times/month, those who consumed legumes ≥4 times/week had an aHR of 1.26 (95% CI, 0.78-2.04; Ptrend = 0.59) for CD and 0.72 (95% CI, 0.44-1.18; Ptrend = 0.20) for UC. Baseline BMI modified the relationship between nut intake and CD risk (Pint = 0.03). In those with BMI ≥25, the aHR for CD was 0.14 (95% CI, 0.03-0.56; P = .006) per additional serving/day of nuts compared with 0.88 (95% CI, 0.45-1.74; P = .72) for those with BMI <25.

CONCLUSIONS

Nut and legume intake were not associated with CD or UC risk. However, higher nut intake decreased CD risk in overweight or obese individuals. Thus, personalized-risk stratification, rather than generalized dietary recommendations, may be important for IBD prevention strategies.

Inflammatory Potential of the Diet and Risk of Crohn's Disease and Ulcerative Colitis

BACKGROUND

Association between dietary factors and the risk of developing inflammatory bowel disease (IBD) has been studied extensively. However, identification of deleterious dietary patterns merits further study.

AIM

To investigate the risk of developing Crohn's disease (CD) and ulcerative colitis (UC) according to the inflammatory score of the diet (ISD) in the multinational European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

METHODS

We used validated food frequency questionnaires collected at baseline to compute ISD scores. We estimated the association between ISD score and risks of CD and UC risks using Cox models stratified by centre, sex and age. We adjusted for smoking status, BMI, physical activity, energy intake, educational level and alcohol intake.

RESULTS

We included 394,255 individuals including 184 incident cases of CD and 459 of UC after median follow-up of 13.6 years (4,889,910 person-years). High ISD scores were associated with a higher risk of CD (fourth vs. first quartile-adjusted HR: 1.88, 95% CI: 1.14-3.10; p-trend < 0.01) but not of UC (adjusted HR: 0.85, 95% CI: 0.63-1.15; p-trend 0.21). For CD, this association was mainly observed for women (adjusted HR: 2.14, 95% CI: 1.17-3.91; p-trend < 0.01). On subgroup analyses, those differences were mainly driven by low intakes of fibre, mono-unsaturated fatty acids, vitamin C, magnesium, onion and alcohol.

CONCLUSIONS

A high ISD score is associated with a higher risk of developing CD but not UC. These results should be taken into account in high-risk populations.

Association between Mediterranean diet and metabolic syndrome: analysis of NHANES 2007-2020

Changing poor dietary habits is effective for treating metabolic syndrome (MetS). Despite the global reputation of the Mediterranean diet (MD) for health, research on its link to MetS is limited, especially in non-Mediterranean regions. This study aimed to investigate the relationship between the MD and MetS. Data from the 2007 to 2020 NHANES were analysed using multiple logistic regression, restricted cubic spline (RCS) regression, and subgroup analysis. Among 20,991 participants, a negative association between Mediterranean diet score (MDS) and MetS prevalence was observed. RCS regression indicated a linear relationship. Subgroup analysis revealed a significant negative association in most groups, except those with high school education, other Hispanics, and non-Hispanic blacks. In the American population, greater adherence to the Mediterranean diet is associated with a reduced risk of metabolic syndrome, emphasising its protective effects and relevance in public health strategies. Future research should focus on promoting its adoption and investigating causal mechanisms and the impact of specific dietary components through longitudinal studies.

Following Through: The Impact of Culinary Medicine on Mediterranean Diet Uptake in Inflammatory Bowel Disease

BACKGROUND

The Mediterranean diet (MD) is recommended for all patients with inflammatory bowel disease (IBD) unless there is a specific contraindication. Culinary medicine has emerged as a method for improving dietary education. Patients and caregivers are often invested in making dietary changes to improve disease control. Here, we examine the dietary preferences of a group of young people with IBD and apply culinary medicine techniques with an in-person MD-focused cooking class.

METHODS

A survey evaluating dietary attitudes was sent to an IBD email listserv at our tertiary care center (n = 779). A validated questionnaire, the Mediterranean Diet Quality Index for Children and Adolescents was used to assess MD adherence. IBD dietitians customized 2 in-person MD-focused cooking classes, one for children 6 to 12 years of age (arm 1) and one for adolescents 13 to 17 years of age (arm 2). Baseline, 1-month follow-up, and 3-month follow-up surveys were completed.

RESULTS

There were 112 survey responses. Participants were 67.0% male with diagnosis of Crohn's disease (50.0%), ulcerative colitis (42.0%), or IBD unclassified (8.0%). Most were managed on advanced therapies (82.0%). Most reported making decisions about diet (82.0%) in order to help with IBD, had met with a dietitian (69.0%), and were interested in learning more about the MD (55.3%). MD scores were primarily in the average (49.5%) and poor (41.1%) diet categories. Only those eating together as a family 3 or more times per week or those who had met with a dietitian scored in the optimal diet category. The median MD score at baseline was 4.5, increasing to 6.0 at 1 month and 7.0 at 3 months postintervention. Almost all (90%) would recommend cooking classes to others. Common barriers to MD uptake included lack of knowledge about which foods to prepare, concern about taste, and time to prepare food.

CONCLUSIONS

This study showcases high patient and caregiver interest in dietary management of IBD and demonstrates efficacy of education via application of culinary medicine. Classes were well received by families and MD adherence scores increased postintervention. As patients with IBD and their families are often motivated to incorporate dietary therapy into their care, this work highlights the role of culinary medicine and value of future study.

A pro-inflammatory diet is associated with growth and virulence of Escherichia coli in pediatric Crohn's disease

BACKGROUND AND AIMS

Epidemiological studies have suggested an association between the inflammatory potential of dietary patterns and Crohn's disease (CD). However, the relationships of these inflammatory dietary determinants with the microbiome remain largely unknown. In this cross-sectional study, we evaluate the association between the inflammatory potential of habitual diet, as assessed by the modified Children-Dietary Inflammatory Index (mC-DII), and the fecal microbiome and metabolome of children with CD in comparison to healthy children.

METHODS

A cross-sectional study including 51 children with CD between 6 and 18 years of age and 50 healthy controls was conducted. Dietary inflammatory potential was measured using the mC-DII, and diet quality was assessed by the Healthy Eating Index (HEI)-2015 and alternate Mediterranean Eating Index (aMed). The microbiome was analyzed using shotgun metagenomic sequencing and untargeted metabolomic analysis.

RESULTS

A poor-quality, pro-inflammatory diet, with similar mC-DII, HEI-2015, and aMed scores, was found across healthy children and children with CD. In children with active disease, a pro-inflammatory diet was associated with decreased diversity, increased virulence potential, and expansion of the Proteobacteria phylum dominated by Escherichia coli (E. coli) spp. A positive correlation between E. coli relative abundance and mC-DII was associated with a low intake of a cluster composed of fibers, vitamins, and minerals with anti-inflammatory potential. A negative association between metabolites of fatty acid metabolism and HEI was found.

CONCLUSIONS

In total, our results suggest that a pro-inflammatory diet may potentiate hallmarks of the inflammation-associated dysbiosis in CD and highlight the need for microbiome-targeted dietary interventions optimizing the anti-inflammatory potential of habitual diet in the management of pediatric CD.

Diet and Microbiome-Directed Therapy 2.0 for IBD

Inflammatory bowel disease (IBD) comprises chronic and relapsing disorders of the gastrointestinal tract, characterized by dysregulated immune responses to the gut microbiome. The gut microbiome and diet are key environmental factors that influence the onset and progression of IBD and can be leveraged for treatment. In this review, we summarize the current evidence on the role of the gut microbiome and diet in IBD pathogenesis, and the potential of microbiome-directed therapies and dietary interventions to improve IBD outcomes. We discuss available data and the advantages and drawbacks of the different approaches to manipulate the gut microbiome, such as fecal microbiota transplantation, next-generation and conventional probiotics, and postbiotics. We also review the use of diet as a therapeutic tool in IBD, including the effects in induction and maintenance, special diets, and exclusive enteral nutrition. Finally, we highlight the challenges and opportunities for the translation of diet and microbiome interventions into clinical practice, such as the need for personalization, manufacturing and regulatory hurdles, and the specificity to take into account for clinical trial design.

Nutritional Habits in Crohn's Disease Onset and Management

Crohn's disease (CD)'s activation factors are still unclear. However, they are reported to involve an interaction between genetic susceptibility and unhealthy lifestyle factors like smoking, alcohol consumption, low physical activity, low BMI (<18.5 kg/m2), and probably unbalanced nutritional habits. Therefore, the aim of the present review is to demonstrate the possible effects of different nutritional habits, before the occurrence of the disease, as crucial factors for the inception of CD activation. The structure of the present narrative review was conducted following the instructions of the "Review Academy of Nutrition and Dietetics Checklist". It is well established that the consumption of specific foods and drinks, such as spicy and fatty foods, raw vegetables and fruits, dairy products, carbonated beverages, and coffee or tea, can provoke the exacerbation of CD symptoms. On the other hand, Mediterranean-oriented diets seem to provide an inverse association with the incidence of CD. Moreover, patients seem to have the knowledge to select foods that contribute to the remission of their symptoms. However, it is not clearly reported whether the onset of CD activation is due to lifelong unbalanced nutritional habits and their subsequent effect on gut microbiota secretion, which seems to be the gold standard for CD's investigation. Therefore, more future studies should record, examine, and compare the nutritional habits between patients with CD (immediately after the disease's diagnosis) and healthy populations in a lifelong manner, in order to reveal the possible influence of foods on CD onset.

From Evidence to Practice: A Narrative Framework for Integrating the Mediterranean Diet into Inflammatory Bowel Disease Management

Emerging evidence underscores the pivotal role of diet in preventing and managing inflammatory bowel disease (IBD). As our comprehension of the microbiome's role in IBD expands, dietary modifications are increasingly recognized as potential adjuncts or primary therapeutic strategies. Key components of the Mediterranean diet (MD)-including microbiota-accessible carbohydrates, omega-3 fatty acids, polyphenols, and antioxidants-have demonstrated promise in enhancing gut microbiota diversity and reducing intestinal inflammation, making it a practical approach for managing IBD. Moreover, the MD offers additional benefits considering the rising prevalence of comorbid chronic inflammatory conditions such as diabetes, cardiovascular disease, and obesity in IBD patients. The purpose of this narrative review was to provide an overview of the feasibility and clinical outcomes of the MD and offer evidence-based guidance for researchers and practitioners on how to adapt the MD to patients with IBD. According to several cross-sectional and interventional studies, the MD is feasible for patients with IBD and confers several benefits, such as reduced inflammation, improved disease activity, and enhanced quality of life, with a strong adherence rate and minimal adverse effects. To facilitate knowledge translation, we provide a practical framework for integrating the MD as a nutritional therapy for IBD, including specific recommendations and messaging that researchers, practitioners, and patients can use. By synthesizing current evidence and offering actionable insights, the aim is to facilitate the integration of the MD into IBD management, with the potential to improve patient outcomes.

Exploring nutritional risks of the specific carbohydrate diet: food and nutrient intake in children with juvenile idiopathic arthritis

Diet is considered a key research priority for juvenile idiopathic arthritis (JIA), garnering considerable interest from affected families. Despite this, research studies focusing on dietary interventions remain scarce. The specific carbohydrate diet (SCD) has shown potential, however, its nutritional consequences and risks are not well understood. This study aims to describe and evaluate food and nutrient intakes in children with JIA adhering to the SCD and contextualize the results relative to recommendations and intakes in the general population. In a secondary analysis, food and nutrient intakes from three-day dietary records of ten children, following a four-week SCD intervention, were evaluated against the Nordic Nutrition Recommendations 2023 and Riksmaten Adolescents data (RMA) (n = 1282). All children following the SCD met the recommended minimum intake of fruit and vegetables of 500g/day, a stark contrast to the 6% in RMA. Median dietary fibre intake for the SCD was 26g/d, (IQR 21-33), compared to 16g/d (IQR 12-22) in RMA. Elevated saturated fatty acid (SFA) intake was observed in both groups, with the SCD group also consuming high amounts of red meat. Calcium was the sole nutrient for which the standard diet surpassed the SCD, as 9 out of 10 participants had inadequate intake. While children on the SCD showed a lower likelihood of nutrient inadequacy compared to the general population, inadequate calcium intake and elevated SFA and red meat consumption are concerning given known comorbidities in JIA. These results highlight the importance of disease-specific dietary guidance to ensure optimal support for patients and parents.

Dietary content and eating behavior in ulcerative colitis: a narrative review and future perspective

Ulcerative colitis (UC) has experienced a steady increase in global incidence and prevalence recently. Current research into UC pathogenesis focuses on the complex interplay of genetic and environmental factors with the immune system and gut microbiome, leading to disruption of the intestinal barrier. Normally, the microbiome, intestinal epithelium, and immune system interact to maintain intestinal homeostasis. However, when this equilibrium is disturbed, a harmful cycle of dysbiosis, immune dysregulation, and inflammation emerges, resulting in intestinal barrier dysfunction and UC progression. Among various risk factors, diet significantly influences epithelial barrier integrity and architectural stability through both direct and indirect mechanisms, shaping the entire UC continuum from pre-clinical prevention to active phase treatment and remission maintenance. This review provides insights into the impact of dietary content and eating behaviors on UC, focusing on specific food, food groups, nutrients, and intermittent fasting, while providing a detailed explanation of why the gut microbiota may mediate the sustained effects of diet across all stages of UC. Additionally, it addresses the limitations of current studies, explores underexamined areas in UC dietary research and proposes potential directions for future research and expansion.

Dietary Interventions and Supplementation in Patients With an Ileal Pouch-Anal Anastomosis: A Systematic Review

The restorative proctocolectomy with ileal pouch–anal anastomosis is the preferred surgery for patients with medically refractory ulcerative colitis. Although the ileal pouch–anal anastomosis provides gastrointestinal continuity and is an excellent alternative to a permanent end ileostomy, it is not without its complications including acute pouchitis, which occurs in up to 80% of patients. Diet may have a significant impact on pouch function and the development of pouchitis by virtue of its impact on motility and the microbiome. Multiple studies have evaluated the ability of different diets and supplements to improve pouch function and manage pouchitis, yet results are conflicting; thus, evidence-based dietary recommendations are lacking. Patients with an ileoanal pouch routinely ask about dietary interventions to maintain pouch health, and it is crucial that concrete evidence-based recommendations are identified to provide guidance. The goal of this systematic review is to summarize the available data on dietary patterns in patients with an ileoanal pouch, dietary interventions in this cohort, and the impact of supplements on pouch function and pouchitis.

Using Diet to Treat Inflammatory Bowel Disease: A Systematic Review

INTRODUCTION

To review the efficacy of various dietary interventions for induction of clinical remission in inflammatory bowel disease (IBD) and provide healthcare providers with a practical reference for recommending suitable diets for managing patients with IBD.

METHODS

PubMed, Medline(R), and Cochrane were searched from inception up to February 17, 2023, to identify all studies reporting information on using diet to treat IBD. Studies investigating the role of dietary interventions in adult patients with a confirmed diagnosis of active IBD for improvement or remission of IBD symptoms were rigorously considered. Sample meal plans, with a list of included and excluded foods, were also generated to provide clinicians with practical tools for advising patients on dietary intake.

RESULTS

Eleven included studies provided data on 10 distinct diets: autoimmune protocol diet, high-fiber diet, 4-strategies-to-SUlfide-Reduction diet, highly restricted diet, McMaster elimination diet for Crohn's disease, specific carbohydrate diet, Mediterranean diet, Crohn's disease exclusion diet, individualized elimination diet, and the food-specific IgG4-guided exclusion diet. A total of 9 studies provided data on clinical remission. Many of these diets share common elements, such as an initial elimination phase with subsequent reintroduction of dietary components, inclusion of whole foods, and exclusion of highly or ultraprocessed foods.

DISCUSSION

Currently, there is limited evidence to support the use of specific diets to treat adult patients with mildly to moderately active IBD. Larger, randomized studies with standardized methodologies and outcome measures, rigorous adherence assessment, and an emphasis on endoscopic assessment outcome measures are required to validate most diets that have been studied for IBD. The included sample diet plans and dietary recommendations may prove helpful in the interim as part of a holistic strategy to manage patients with IBD.

The Role of Diet in Inflammatory Bowel Disease Onset, Disease Management, and Surgical Optimization

The concept of using diet as therapy in inflammatory bowel disease is of interest to clinicians and patients. Once considered to play a minor role, diet is now known to not only affect disease onset but may also serve as a therapeutic tool for inducing and maintaining remission and improving surgical outcomes. Further research is needed to fully elucidate how, when, and in whom diet therapies may be best applied to improve clinical and disease outcomes. The aim of this review was to summarize current research findings and serve as a tool to help facilitate patient-clinician conversations.

Metabolomic Signatures Highlight Fiber-Degrading Bacteroides Species in Mediterranean Diet Response Among Ulcerative Colitis

Background and Aims

The Mediterranean diet pattern (MDP) is associated with health-associated gut microbes and metabolites. However, the impact of the MDP on the fecal metabolome in ulcerative colitis (UC) remains unclear. We characterized the fecal metabolome of patients with UC with high adherence to the MDP compared to the Canadian habitual diet (CHD). Furthermore, we explored potential differences in the fecal metabolome between dietary responders and nonresponders to the MDP.

Methods

Utilizing untargeted metabolomics on a subset of fecal samples obtained from a randomized controlled trial, adult patients with quiescent UC underwent a 12-week intervention following either the MDP (n = 8) or CHD (n = 8). Liquid chromatography-tandem mass spectrometry was employed to profile endogenous fecal metabolites, while 16S amplicon sequencing was utilized to profile the fecal microbiota.

Results

A total of 701 human metabolites were detected, with 35 exhibiting significant differential expression between the MDP and CHD groups. Noteworthy, folate biosynthesis, sphingolipid biosynthesis, and steroid biosynthesis were identified as major pathways affected. Moreover, microbial analysis showed that individuals with increased levels of the class Bacteroidia (Bacteroides vulgatus [B. vulgatus], B. uniformis, and B. acidifaciens) in their stool at baseline were more likely to respond to the MDP.

Conclusion

High adherence to an MDP is associated with beneficial metabolite changes associated with reducing inflammation in UC. In addition, fiber-degrading microbes abundant before dietary intervention played a role in the responsiveness to the MDP. This work lays the groundwork for developing a metabolic signature associated with the MDP to develop personalized nutrition strategies for UC prevention and treatment. ClinicalTrials.gov Number: NCT03053713.

Modified Crohn's Disease Exclusion Diet Maintains Remission in Pediatric Crohn's Disease: Randomized Controlled Trial

BACKGROUND & AIMS

The Crohn's disease exclusion diet (CDED) + partial enteral nutrition (PEN) is effective for inducing remission in mild-moderate Crohn's disease (CD). We assessed whether a 2-week course of exclusive enteral nutrition (EEN) followed by CDED+PEN is superior to 8 weeks of EEN in sustaining clinical remission at week 14 in mild-to-severe CD and if CDED+PEN can maintain remission to week 24.

METHODS

This international, multicenter, randomized controlled trial compared 2 weeks of EEN (Modulen IBD) followed by 3 phases of the CDED+PEN (henceforth CDED) to 8 weeks of EEN, followed by PEN with free diet up to week 24 (henceforth EEN).

RESULTS

Out of 64 eligible patients, 56 were randomized (target recruitment failed due to the COVID-19 pandemic, leading to an underpowered study): 30 patients to CDED and 26 to EEN. The primary endpoint at week 14 showed no significant difference between the groups, with sustained corticosteroid-free remission in 21 (70%) of 30 for CDED compared with 16 (61.5%) of 26 for EEN (P = .5). At week 8, clinical remission was achieved in 23 (77%) of 30 CDED patients vs 14 (54%) of 26 EEN patients (P = .07), and 18 (60%) of 30 CDED patients vs 11 (42%) of 26 EEN patients maintained clinical remission to week 24 (P = .18). The body mass index Z score significantly improved in the CDED group but not in the EEN group.

CONCLUSIONS

The study was underpowered to show whether CDED was superior to EEN in sustaining remission. However, 2 weeks of EEN followed by CDED was effective in inducing remission in CD, with most CDED patients maintaining remission up to 24 weeks. Despite dietary restrictions for 24 weeks, the body mass index Z score improved significantly in the CDED group but not in the EEN group (NCT02843100).

Nutritional management and autism spectrum disorder: A systematic review

BACKGROUND

Autism spectrum disorder (ASD) presents unique challenges related to feeding and nutritional management. Children with ASD often experience feeding difficulties, including food selectivity, refusal, and gastrointestinal issues. Various interventions have been explored to address these challenges, including dietary modifications, vitamin supplementation, feeding therapy, and behavioral interventions.

AIM

To provide a comprehensive overview of the current evidence on nutritional management in ASD. We examine the effectiveness of dietary interventions, vitamin supplements, feeding therapy, behavioral interventions, and mealtime practices in addressing the feeding challenges and nutritional needs of children with ASD.

METHODS

We systematically searched relevant literature up to June 2024, using databases such as PubMed, PsycINFO, and Scopus. Studies were included if they investigated dietary interventions, nutritional supplements, or behavioral strategies to improve feeding behaviors in children with ASD. We assessed the quality of the studies and synthesized findings on the impact of various interventions on feeding difficulties and nutritional outcomes. Data extraction focused on intervention types, study designs, participant characteristics, outcomes measured, and intervention effectiveness.

RESULTS

The review identified 316 studies that met the inclusion criteria. The evidence indicates that while dietary interventions and nutritional supplements may offer benefits in managing specific symptoms or deficiencies, the effectiveness of these approaches varies. Feeding therapy and behavioral interventions, including gradual exposure and positive reinforcement, promise to improve food acceptance and mealtime behaviors. The findings also highlight the importance of creating supportive mealtime environments tailored to the sensory and behavioral needs of children with ASD.

CONCLUSION

Nutritional management for children with ASD requires a multifaceted approach that includes dietary modifications, supplementation, feeding therapy, and behavioral strategies. The review underscores the need for personalized interventions and further research to refine treatment protocols and improve outcomes. Collaborative efforts among healthcare providers, educators, and families are essential to optimize this population's nutritional health and feeding practices. Enhancing our understanding of intervention sustainability and long-term outcomes is essential for optimizing care and improving the quality of life for children with ASD and their families.

The Key Nutrients in the Mediterranean Diet and Their Effects in Inflammatory Bowel Disease: A Narrative Review

The gut microbiome, a collection of gut microorganisms, is crucial in the development and progression of inflammatory bowel diseases (IBD). Therefore, diet and dietary interventions are promising strategies to shape the gut microbiota for IBD management. Of all the diets studied in the IBD field, the Mediterranean diet has the least restrictive nature, promoting long-term adherence. The Mediterranean diet is rich in plants, with a high daily intake of fruits and vegetables (high in fiber, antioxidants, and vitamins), olive oil, whole grains, legumes, and nuts. It includes the moderate consumption of animal products such as oily fish (rich in mono- and polyunsaturated fatty acids), dairy products, and poultry, with a limited intake of red meat and processed foods. This diet is associated with a decreased risk of chronic diseases, including IBD. However, the mechanisms of specific nutrients behind these effects in the Mediterranean diet remain under investigation. Therefore, in this review, we aim to provide an overview of the nutrients that are abundant in the Mediterranean diet and their effects on IBD, with a main focus on preclinical evidence. While several nutrients like fructo-oligosaccharide, chitosan, plant-derived protein, polyphenols, omega-3 polyunsaturated fatty acids, and resveratrol have shown potential beneficial effects in preclinical models, clinical evidence is often limited. However, understanding the complex interactions between specific nutrients and IBD is essential to developing a tailored, multidisciplinary, and personalized approach for disease management; therefore, further research is required.

Chronic Abdominal Pain in Patients with Inflammatory Bowel Disease in Remission: A Continuing Challenge for Clinicians

Inflammatory bowel disease (IBD) is a chronic condition that includes ulcerative colitis and Crohn's disease. It is characterized by a relapsing and remitting pattern that negatively impacts quality of life (QoL). Current goals of treatment involve symptomatic, biochemical, and endoscopic remission in a treat-to-target approach. Despite effective treatment and remission of IBD, many patients report frequent and isolated abdominal pain. A wide range of etiologies exist, including surgery-related, infections, pelvic conditions, immune-related, and systemic illnesses. Disorders of the gut-brain interaction (DGBI), frequently characterized by abdominal pain, are increasingly recognized in IBD patients, including those with quiescent disease. Various mechanisms are involved and numerous non-pharmacologic and pharmacologic therapies have been proposed. Hereby, we outline the pertinent findings of the literature on management of chronic abdominal pain, focusing on quiescent IBD.

The intestinal microbiome, but not clinical aspects of inflammatory bowel disease, is impacted by lactose malabsorption compared to lactose digestion in children

BACKGROUND

Dietary exclusion of lactose from patients with inflammatory bowel disease (IBD) persists with speculation that deleterious effects are mediated through intestinal microbes.

OBJECTIVES

To compare IBD characteristics and changes in the intestinal microbiome (IM) at diagnosis in children with and without lactose malabsorption (LM).

METHODS

A cross-sectional cohort of children (8-17 y of age) diagnosed with Crohn's disease [n = 149 (63%)] or ulcerative colitis (n = 86) that had undergone lactose breath hydrogen testing was evaluated. The IM of mucosal luminal aspirates was profiled at the time of diagnosis using 16S ribosomal ribonucleic acid gene amplicon sequencing of the V6 hypervariable region.

RESULTS

Of the 235 children, 61 (26%) had LM. Microbial characterization yielded differences in bacterial differential abundance between children who could and could not absorb lactose, which varied by intestinal site and between subtypes of IBD. There were no differences in the ages [13.2 ± 3.0 y (mean ± standard deviation) compared with 12.7 ± 3.4 y; P = 0.25], sex (P = 0.88), extent of disease involvement or severity of disease at presentation (P = 0.74) when comparing those that could or could not absorb lactose nor was there a difference in the need for initiation of biological agents (P = 0.43) during 2 y of follow-up.

CONCLUSIONS

LM does not affect the clinical presentation or outcomes of children with IBD. However, this study establishes that a single nonabsorbed fermentable food product can alter the IM in both a regional and disease-specific manner. As we continue to learn more about the pathophysiology of IBD and the role of the IM in disease onset and progression, it would be of benefit to examine the impact of other potential fermentable nutrients and their products on IBD outcomes.

A pilot randomized controlled trial investigating the effects of an anti-inflammatory dietary pattern on disease activity, symptoms and microbiota profile in adults with inflammatory bowel disease

BACKGROUND/OBJECTIVES

There is a lack of certainty in dietary prescription for individuals with inflammatory bowel disease (IBD) due to heterogeneity in studies to date. The aim of this study was to investigate the efficacy on disease activity of a modified anti-inflammatory dietary pattern purposely designed to reduce intake of food additives (IBD-MAID), compared to standard care, in adults with IBD.

SUBJECT/METHODS

Adults with IBD were randomised to IBD-MAID (meals provided) [n = 29] or general healthy eating (GHE) [n = 29] for 8 weeks. Disease activity, faecal calprotectin (FC), C-reactive protein (CRP), symptoms, and quality of life (S&QOL) were assessed using validated tools.

RESULTS

The IBD-MAID was well tolerated and adhered to (92% adherence). At week 8, there was no statistically significant difference in change from baseline in outcome measures between groups. However, baseline to week 8 analysis indicated: (1) statistically significant improvements in S (p = 0.001) & QOL (p = 0.004), FC (p = 0.007), and Crohn's disease activity (p = 0.03) but not ulcerative colitis, in individuals following the IBD-MAID and (2) statistically significant improvement in QOL in individuals receiving GHE (p = 0.015). Correlation analysis on change from baseline to week 8 revealed a greater decrease in food additives intake was associated with statistically significant improvements in FC, S & QOL and alignment of anti-inflammatory dietary principles with improvements in QOL.

CONCLUSION

The IBD-MAID was well tolerated. The most novel finding pertains to the correlation between reduced food additives intake and improvements in inflammatory markers, S&QOL. Further research is needed to explore the effects of food additives exposure on IBD course.

TRIAL REGISTRATION

12619001500145.

Adjunct Therapies to Standard Care for IBS and IBD Patients: Digestive Symptoms Improvement and Quality of Life Optimization

Background: The prevalence of both inflammatory bowel diseases (IBD) and Irritable Bowel Syndrome (IBS) is increasing, with persistent digestive symptoms, an altered quality of life, and higher rates of anxiety, chronic fatigue, and sleep trouble than the general population. Methods: This scoping review will analyze the latest clinical practice recommendations and clinical studies on non-pharmaceutical interventions such as diet adaptations, physical activity, cognitive behavioral therapies, and medical nutrition therapies such as probiotics, soluble fibers, chitin-glucan, and micronutrients for digestive symptoms relief, quality of life improvement and nutritional deficiencies correction in IBS and IBD patients. The objective is to help healthcare practitioners and dietitians to build personalized care program for IBD and IBS patients. Results: Mediterranean diet, physical activity, cognitive behavioral therapies and medical nutrition therapies such as selected probiotics, soluble fibers, chitin glucan, peppermint oil and micronutrients are effective as adjunct therapies. Conclusions: These adjunct therapies may help to reduce persistent digestive symptoms, correct nutritional deficiencies and improve quality of life of IBS and IBD patients.

The interplay between diet and the gut microbiome: implications for health and disease

Diet has a pivotal role in shaping the composition, function and diversity of the gut microbiome, with various diets having a profound impact on the stability, functionality and diversity of the microbial community within our gut. Understanding the profound impact of varied diets on the microbiome is crucial, as it will enable us not only to make well-informed dietary decisions for better metabolic and intestinal health, but also to prevent and slow the onset of specific diet-related diseases that stem from suboptimal diets. In this Review, we explore how geographical location affects the gut microbiome and how different diets shape its composition and function. We examine the mechanisms by which whole dietary regimes, such as the Mediterranean diet, high-fibre diet, plant-based diet, high-protein diet, ketogenic diet and Western diet, influence the gut microbiome. Furthermore, we underscore the need for exhaustive studies to better understand the causal relationship between diet, host and microorganisms for the development of precision nutrition and microbiome-based therapies.

Review article: Evidence-based dietary management of inflammatory bowel disease

BACKGROUND

Dietary management of patients with inflammatory bowel disease (IBD) involves more than defining a therapeutic diet. The profusion of 'expert advice' is not necessarily built on evidence.

AIMS

To provide evidence-based guidance on all clinically relevant aspects of nutritional and dietary management of patients with IBD.

METHODS

A comprehensive review of the published literature was made.

RESULTS

Four pillars of management should be considered in all patients. First, nutritional status should be optimised, since myopenia and visceral obesity are associated with poorer outcomes, which can be improved with attention to their correction. Accurate point-of-care measurement of body composition is advocated to identify problems, guide interventions and monitor outcomes. Second, exclusive enteral nutrition and the Crohn's Disease Exclusion Diet with partial enteral nutrition in reducing intestinal inflammation in patients with Crohn's disease have sufficient evidence to be advocated. Multiple other dietary approaches, while promising, have insufficient evidence to be recommended. Third, dietary approaches are important in symptomatic control in many non-inflammatory scenarios. Finally, guidance on following a healthy diet is fundamental to the general health of patients. Multiple approaches are advocated, but the optimal strategy is unclear. The precarious nutritional status of patients with IBD together with the risks of nutritional inadequacy and maladaptive eating behaviours associated with restrictive diets dictate involvement of expert dietitians in assessment and personalised delivery of dietary interventions.

CONCLUSIONS

Four pillars of nutritional management require specific assessment and interventional strategies that should be chosen by evidence. Optimal delivery requires the skills of a specialised dietitian.

Metaproteomics reveals diet-induced changes in gut microbiome function according to Crohn's disease location

BACKGROUND

Crohn's disease (CD) is characterized by chronic intestinal inflammation. Diet is a key modifiable factor influencing the gut microbiome (GM) and a risk factor for CD. However, the impact of diet modulation on GM function in CD patients is understudied. Herein, we evaluated the effect of a high-fiber, low-fat diet (the Mi-IBD diet) on GM function in CD patients. All participants were instructed to follow the Mi-IBD diet for 8 weeks. One group of CD patients received one-time diet counseling only (Gr1); catered food was supplied for the other three groups, including CD patients (Gr2) and dyads of CD patients and healthy household controls (HHCs) residing within the same household (Gr3-HHC dyads). Stool samples were collected at baseline, week 8, and week 36, and analyzed by liquid chromatography-tandem mass spectrometry.

RESULTS

At baseline, the metaproteomic profiles of CD patients and HHCs differed. The Mi-IBD diet significantly increased carbohydrate and iron transport and metabolism. The predicted microbial composition underlying the metaproteomic changes differed between patients with ileal only disease (ICD) or colonic involvement: ICD was characterized by decreased Faecalibacterium abundance. Even on the Mi-IBD diet, the CD patient metaproteome displayed significant underrepresentation of carbohydrate and purine/pyrimidine synthesis pathways compared to that of HHCs. Human immune-related proteins were upregulated in CD patients compared to HHCs.

CONCLUSIONS

The Mi-IBD diet changed the microbial function of CD patients and enhanced carbohydrate metabolism. Our metaproteomic results highlight functional differences in the microbiome according to disease location. Notably, our dietary intervention yielded the most benefit for CD patients with colonic involvement compared to ileal-only disease. Video Abstract.

Recommendations for Designing, Conducting, and Reporting Feeding Trials in Nutrition Research

Double-blind, placebo-controlled, randomized controlled trials are the gold standard for clinical trials in nutrition science. For trials of whole diets, dietary counseling is advantageous as they offer clinical translatability although can vary in the fidelity of the intended intervention from participant to participant and across studies. Feeding trials, in which most or all food is provided, offer high precision and can provide proof-of-concept evidence that a dietary intervention is efficacious and can also better evaluate the effect of known quantities of foods and nutrients on physiology. However, they come with additional methodological complexities. Feeding trials also call for a variety of unique methodological considerations, not least of which relate to the design and delivery of diets to participants. This review aims to provide a comprehensive summary of recommendations for design and conduct of feeding trials, encompassing domiciled and nondomiciled feeding trials. Several pertinent aspects of trial design and methodology are discussed, including defining the study population to maximize retention, safety, and generalizability of findings, recommendations for design of control interventions and optimizing blinding, and specific considerations for clinical populations. A detailed stepwise process for menu design, development, validation, and delivery are also presented. These recommendations aim to facilitate methodologic consistency and execution of high-quality feeding trials, ultimately facilitating improved understanding of the role of diet in treating disease and the underpinning mechanisms.

Examining dietary interventions in Crohn's disease

This editorial builds on the article by Shakhshir et al. We conducted an overview of evidence-based dietary interventions in adults with inflammatory bowel disease (IBD). In the IBD population, there may be a role for the Mediterranean diet due to its anti-inflammatory effects, long-term sustainability, and role in improving cardiovascular health. In active Crohn's disease, the use of exclusive enteral nutrition, the Crohn's disease exclusion diet, or the specific carbohydrate diet may be used as a short-term adjunct to medical therapy and may improve mucosal healing. The low-FODMAP diet can assist in reducing symptoms for patients without evidence of active bowel inflammation. As interest in nutritional therapy increases amongst clinicians and patients alike, it is integral that dietary therapies are understood and discussed in routine management of patients with IBD as part of holistic care, ideally through a multidisciplinary setting with involvement of experienced dietitians. This serves to improve clinician-patient engagement and reduce complications of IBD including micro and micronutrient deficiencies.

An Overview of Nutritional Interventions in Inflammatory Bowel Diseases

Food is an important environmental factor in the development of inflammatory bowel diseases, chronic immune-mediated diseases of the gastrointestinal tract. Consequently, there is significant focus on the role that dietary approaches might have in the management of these diseases. The introduction of exclusive enteral nutrition (EEN) as a treatment option for induction of remission in Crohn's disease was a breakthrough in disease pathophysiology understanding and has paved the way for dietary options based on this understanding. This review aims to summarize the current data on the effect of different available diets on disease symptoms and the inflammatory process.

Restore Intestinal Barrier Integrity: An Approach for Inflammatory Bowel Disease Therapy

The intestinal barrier maintained by various types of columnar epithelial cells, plays a crucial role in regulating the interactions between the intestinal contents (such as the intestinal microbiota), the immune system, and other components. Dysfunction of the intestinal mucosa is a significant pathophysiological mechanism and clinical manifestation of inflammatory bowel disease (IBD). However, current therapies for IBD primarily focus on suppressing inflammation, and no disease-modifying treatments specifically target the epithelial barrier. Given the side effects associated with chronic immunotherapy, effective alternative therapies that promote mucosal healing are highly attractive. In this review, we examined the function of intestinal epithelial barrier function and the mechanisms of behind its disruption in IBD. We illustrated the complex process of intestinal mucosal healing and proposed therapeutic approaches to promote mucosal healing strategies in IBD. These included the application of stem cell transplantation and organ-like tissue engineering approaches to generate new intestinal tissue. Finally, we discussed potential strategies to restore the function of the intestinal barrier as a treatment for IBD.

The effect of solid food diet therapies on the induction and maintenance of remission in Crohn's disease: a systematic review

BACKGROUND

The efficacy of highly restrictive dietary therapies such as exclusive enteral nutrition (EEN) in the induction of remission in Crohn's disease (CD) are well established, however, ongoing issues exist with its poor palatability, restrictions, and adherence. The primary aim of this review is to evaluate the current evidence for the efficacy of exclusively solid food diets on the induction and maintenance of clinical and biochemical remission in CD. Secondary aims include impact on endoscopic healing and quality of life.

METHODS

A systematic review of all randomised controlled trials (RCTs), open-label randomised trials and head-to-head clinical trials assessing solid food diet intervention in patients with active or inactive Crohn's disease was conducted. Studies included adult and paediatric patients with a verified disease activity index at baseline and follow up (Harvey Bradshaw Index, HBI; Crohn's disease activity index, CDAI and paediatric CDAI, PCDAI). Additional secondary endpoints varied between studies, including endoscopic and biochemical responses, as well as quality of life measures. Two authors independently performed critical appraisals of the studies, including study selection and risk of bias assessments.

RESULTS

14 studies were included for review, with several studies suggesting clinically significant findings. Clinical remission was achieved in a paediatric population undertaking the Mediterranean diet (MD) (moderate risk of bias). In adults, the Crohn's disease exclusion diet (CDED) was comparable to the CDED with partial enteral nutrition (PEN) diet in induction of remission (moderate risk of bias). A low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet was also shown to decrease symptoms in patients with quiescent or mildly active CD (high risk of bias), however, this was not corroborated by other low FODMAP diet studies.

CONCLUSIONS

There are promising outcomes for the MD and CDED in inducing clinical remission in mild to moderate CD. The results need to be interpreted with caution due to design limitations, including issues with combining outcomes among CD and UC patients, and small sample size. The current evidence for solid food dietary therapy in CD is limited by the lack of high quality studies and moderate to high bias. Future well designed studies are needed to confirm their efficacy.