Crohn's disease (CD) is a chronic inflammatory bowel disorder frequently associated with significant nutritional deficiencies. Enteral nutrition (EN), particularly exclusive enteral nutrition (EEN), has gained recognition not only for its nutritional support but also for its therapeutic potential in reducing intestinal inflammation. While EEN is well established in pediatric populations, its application in adults remains limited due to lower adherence and palatability challenges. Nonetheless, emerging evidence supports its efficacy in various clinical settings, including as an adjunct to pharmacologic therapies and in mitigating pre- and postoperative disease burden. The heterogeneity of study designs, formula compositions, and clinical protocols underscores the need for standardized guidelines and personalized approaches. This narrative review synthesizes the current evidence on the role of EN in adult patients with CD, with a focus on its use for induction and maintenance of remission, as well as perioperative optimization.

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.

Advice to avoid dietary emulsifiers in Crohn's disease (CD) is based on preclinical data.

To examine the effect of diets high (HED) and low (LED) in emulsifiers in the food supply on disease activity in CD.

In a double-blinded, randomised feeding study, we randomised adults with symptomatic, sonographically active CD with ileal involvement on ≥ 2 months' stable medical therapy to 4 weeks of a HED or LED modelled on Australian healthy eating guidelines. We measured the Harvey-Bradshaw Index (HBI), sonographic indices (IBUS-SAS, bowel wall thickness), quality of life (QOL) and fatigue at baseline and study completion.

We randomised 24 patients, mean age 37 (95% CI 32, 41) years, 12 male, HBI 6 (6, 8), bowel wall thickness 6.0 (5.5-6.6) mm. Adherence was > 95%. Clinical remission (HBI < 5) occurred in 9/12 on HED and 7/12 on LED; 2 and 3, respectively, withdrew early with increasing gastrointestinal symptoms. IBUS-SAS fell from 51 (35, 68) to 33 (15, 51) on HED (p = 0.014) and from 57 (38, 76) to 44 (29, 59) on LED (p = 0.01). Bowel wall thickness reduced by 34% on HED and 15% on LED in those who completed the study. QOL and fatigue improved on both diets (p ≤ 0.05). There were no statistically significant differences in outcomes between diets.

In the context of a healthy diet, the emulsifier content had no influence over disease activity over 4 weeks in patients with CD. Recommendations to avoid emulsifiers in patients with active CD are not supported. Australian New Zealand Clinical Trials Registry (ACTRN12619001099112).

This systematic literature review (SLR) aims to compare the clinical, humanistic, and economic outcomes associated with specialized and standard nutritional formulas for the treatment of mild-to-moderate pediatric Crohn's disease.

Search strategies were applied across MEDLINE, Cochrane and Web of Science (January 2000-October 2023) and recent congress proceedings (January 2021-October 2023). PRISMA-P guidelines were followed. Quality assessment evaluated risk of bias.

Twenty-three unique studies met the inclusion criteria. Nineteen studies (754 patients) evaluated specialized formula, 10 assessed standard formula (246 patients). Mucosal healing (7 studies), induction (20 studies) and maintenance of remission (9 studies) were reported over various timeframes. High proportions of patients who received specialized formula achieved mucosal healing (63-89% 8 weeks; 25-74% 10 weeks), and remission (50-100% 8 weeks). Specialized formula sustained remission (34-62.5% 6 months and 24-87.5% 1 year). Results were not directly comparable with standard formula due to significant heterogeneity in study methodology, patient populations, and remission definition.

The evidence predominantly supports the benefits of specialized formula in inducing mucosal healing, remission, and sustaining positive outcomes across multiple timepoints. Direct comparison of nutritional interventions is required to further support the findings of this SLR.Protocol registration: PROSPERO CRD42023472370.

People diagnosed with Inflammatory bowel disease (IBD) often have severe dietary restrictions and avoidance due to the uncertainty of intestinal symptoms. Inadequate dietary intake may increase the risk of malnutrition and result in impaired food-related quality of life (FRQoL). Few studies investigated factors influencing FRQoL in patients with IBD. This study aimed to synthesize the existing evidence regarding FRQoL among patients with IBD, including the current situation, measurement instruments, and related influencing factors.

The comprehensive literature search was conducted in databases including PubMed, Embase, CINAHL, PsycInfo, Cochrane Library, as well as the most commonly used Chinese databases (CNKI, Wanfang and CBM). Studies published between January 2015 and December 2023 on FRQoL in patients with IBD were included. The Joanna Briggs Institute (JBI) critical appraisal checklist was utilized to evaluate the methodological quality of the selected studies.

Finally, only five studies met the inclusion criteria were reviewed, including three cross-sectional studies and two case-control studies. The Food-related quality of life-29 Scale (FR-QoL-29) with a total core of 145 was the most used instrument measuring FRQoL in patients with IBD. The mean scores of FRQoL ranged from 69.9 to 102.3 in adult patients with IBD and 94.3 in children. A diverse range of factors were associated with FRQoL, including socio-demographic, clinical, psychological, diet-related, and nutrient intake factors.

The main influencing factors of FRQoL among patients with IBD included disease activity status, severe symptoms, history of IBD surgery, negative emotion reaction, and restrictive eating behaviour. Clinicians should work in concert with dietitians, keeping an eye on the disease status, nutrition intake, and restrictive eating habits, assessing FRQoL and providing personalized dietary recommendation for the patients with IBD.

Crohn's disease (CD) exclusion diet combined with partial enteral nutrition (CDED + PEN) or exclusive enteral nutrition (EEN) is effective in inducing remission in mild-to-moderate pediatric CD. Although CDED + PEN is better tolerated and has higher compliance compared to EEN, a subset of patients does not achieve remission. Diet-induced remission is shown to be positively associated with specific changes in tryptophan-metabolites.

To investigate whether the abundance of baseline fecal tryptophan-metabolites predicts dietary therapy outcomes in pediatric CD.

Diagnostic accuracy study and secondary analysis of previously conducted Randomized Controlled Trial (RCT).

Twenty-six patients from previously performed RCT of mild-to-moderate pediatric CD were included. The patients were classified as having clinical remission (R) (n = 19 in total; CDED + PEN = 10 and to EEN = 9) or No-Remission (NR) (n = 7 in total; CDED + PEN = 3 and EEN = 4) following 6 weeks of therapy, based on the Pediatric Crohn's Disease Activity Index score (⩽10 = remission). We performed a targeted quantitative analysis of 21 tryptophan-metabolites in baseline (t = 0) fecal samples from both groups, utilizing liquid chromatography coupled with quadrupole mass spectrometry. Receiver operator characteristic curve (ROC) and random forest analysis (RFA) were used to assess the predictive power of fecal tryptophan-metabolites for dietary outcomes at baseline. Ratios of tryptophan-metabolites were compared to investigate different downstream tryptophan pathways.

Baseline fecal kynurenine level was significantly higher in NR compared to R for CDED + PEN (p = 0.02) and EEN (p = 0.04). ROC analysis highlighted the robust predictive power of kynurenine for CDED + PEN (area under the curve (AUC = 0.97)) and EEN (AUC = 0.88)-induced remission. RFA corroborated these observations. The ratio serotonin/kynurenine was the strongest predictor of CDED + PEN-induced remission (AUC = 1). The ratio 5-hydroxytryptophan/kynurenine (AUC = 0.88) predicted EEN-induced remission. By combining data from CDED + PEN and EEN, kynurenine (AUC = 0.91) and ratios of quinolinic acid/kynurenine (AUC = 0.93) and kynurenine/indole-3-acetic acid (AUC = 0.88) demonstrated strong predictive performance for dietary therapy-induced remission.

Baseline tryptophan metabolites have the potential to serve as a biomarker for dietary remission in pediatric CD. Some tryptophan metabolite ratios showed the most promising predictive capabilities. If confirmed in validation studies, baseline fecal tryptophan markers may be able to provide much-needed guidance to personalize dietary intervention within the management of pediatric CD.

NCT01728870.

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.

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.

Exclusive enteral nutrition (EEN) is a first-line therapy for pediatric Crohn's disease (CD), but protective mechanisms remain unknown. We established a prospective pediatric cohort to characterize the function of fecal microbiota and metabolite changes of treatment-naive CD patients in response to EEN (German Clinical Trials DRKS00013306). Integrated multi-omics analysis identified network clusters from individually variable microbiome profiles, with Lachnospiraceae and medium-chain fatty acids as protective features. Bioorthogonal non-canonical amino acid tagging selectively identified bacterial species in response to medium-chain fatty acids. Metagenomic analysis identified high strain-level dynamics in response to EEN. Functional changes in diet-exposed fecal microbiota were further validated using gut chemostat cultures and microbiota transfer into germ-free Il10-deficient mice. Dietary model conditions induced individual patient-specific strain signatures to prevent or cause inflammatory bowel disease (IBD)-like inflammation in gnotobiotic mice. Hence, we provide evidence that EEN therapy operates through explicit functional changes of temporally and individually variable microbiome profiles.

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.

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

The management of patients with inflammatory bowel disease (IBD) aims to control inflammation through the use of immunosuppressive treatments that target various points in the inflammatory cascade. However, the efficacy of these therapies in the long term is limited, and they often are associated with severe side effects. Although the pathophysiology of the disease is not completely understood, IBD is regarded as a multifactorial disease that occurs due to an inappropriate immune response in genetically susceptible individuals. The gut microbiome is considered one of the main actors in the development of IBD. Gut dysbiosis, characterised by significant changes in the composition and functionality of the gut microbiota, often leads to a reduction in bacterial diversity and anti-inflammatory anaerobic bacteria. At the same time, bacteria with pro-inflammatory potential increase. Although changes in microbiome composition upon biological agent usage have been observed, their role as biomarkers is still unclear. While most studies on IBD focus on the intestinal bacterial population, recent studies have highlighted the importance of other microbial populations, such as viruses and fungi, in gut dysbiosis. In order to modulate the aberrant immune response in patients with IBD, researchers have developed therapies that target different players in the gut microbiome. These innovative approaches hold promise for the future of IBD treatment, although safety concerns are the main limitations, as their effects on humans remain unknown.

Exclusive enteral nutrition (EEN) is the recommended first-line induction treatment in pediatric patients with active luminal Crohn's disease (CD). We aimed to provide a nationwide overview of evolving EEN practices during an era of increasing biologic use.

We analyzed a prospectively identified nationwide cohort of newly diagnosed pediatric patients with CD in Scotland between January 1, 2015, and June 30, 2022. Patients who received EEN for any indication were divided into 6-monthly epochs and examined over time. Differences during the COVID-19 pandemic (March 16, 2020, to July 19, 2021) were examined. Data were retrospectively collected from electronic medical records: demographics, anthropometrics, concomitant treatments, aspects of EEN administration, and remission/response rates. Descriptive statistics and linear regression were used for analyses.

A total of 649 patients with CD were identified (63% male; median age 12.6 [interquartile range, 10.8-14.8] years); 497 (77%) of 649 received EEN as postdiagnosis induction therapy with a median course length of 7.7 (interquartile range, 5.9-8.0) weeks. Including repeat courses, 547 EEN courses were examined. An increasing incidence of CD was observed over time with no significant changes in EEN usage, remission or response rates, nasogastric tube usage, or course completion (all P > .05). Increasing use of EEN combined with biologics (combination induction) as first-line induction was observed over time (P < .001). Considering COVID-19, lower rates of EEN usage were observed (P = .008) with no differences in remission, oral administration, and course completion rates (all P > .05).

Over the past 7.5 years, except during the COVID-19 pandemic, EEN usage rates have not changed despite an increase in biologic use, although combination induction is an emerging trend.

The aims of this study were to develop and evaluate a high/low-emulsifier diet and compare emulsifier content with preclinical studies that have associated Crohn's disease with emulsifiers.

Supermarkets were audited with a seven-day high- (HED) and low-emulsifier diet (LED) meal plan developed. The emulsifier content of food was sought from food manufacturers, compared to acceptable daily intake (ADI), and doses were provided in trials. Nutritional composition analysis was completed. Healthy adults ate these diets for seven days in a randomized single-blinded cross-over feeding study to assess palatability, tolerability, satiety, food variety, dietary adherence, blinding and the ease of following the meal plan via visual analogue scale.

A database of 1680 foods was created. There was no difference in nutritional content between the HED and LED, except HED had a higher ultra-processed food content (p < 0.001). The HED contained 41 emulsifiers, with 53% of the products able to be quantified for emulsifiers (2.8 g/d), which did not exceed the ADI, was similar to that in observational studies, and was exceeded by doses used in experimental studies. In ten participants, diets were rated similarly in palatability-HED mean 62 (5% CI 37-86) mm vs. LED 68 (54-82) mm-in tolerability-HED 41 (20-61) mm vs. LED 55 (37-73) mm-and in satiety HED 57 (32-81) mm vs. LED 49 (24-73) mm. The combined diets were easy to follow (82 (67-97) mm) with good variety (65 (47-81)) and excellent adherence.

Nutritionally well-matched HED and LED were successfully developed, palatable and well tolerated.

Ultra-processed foods (UPFs) and food additives have become ubiquitous components of the modern human diet. There is increasing evidence of an association between diets rich in UPFs and gut disease, including inflammatory bowel disease, colorectal cancer and irritable bowel syndrome. Food additives are added to many UPFs and have themselves been shown to affect gut health. For example, evidence shows that some emulsifiers, sweeteners, colours, and microparticles and nanoparticles have effects on a range of outcomes, including the gut microbiome, intestinal permeability and intestinal inflammation. Broadly speaking, evidence for the effect of UPFs on gut disease comes from observational epidemiological studies, whereas, by contrast, evidence for the effect of food additives comes largely from preclinical studies conducted in vitro or in animal models. Fewer studies have investigated the effect of UPFs or food additives on gut health and disease in human intervention studies. Hence, the aim of this article is to critically review the evidence for the effects of UPF and food additives on gut health and disease and to discuss the clinical application of these findings.

Enteral nutrition (EN) involves replacing all or part of a person's habitual diet with a nutritional formula. The impact of varying doses of EN on the gut microbiome remains understudied.

Healthy adults replaced all (100% EN) or part (85% EN, 50% EN and 20% EN) of their energy requirements with EN for 7 days. Faecal samples were collected before and on day 7 of interventions. Faecal pH, short chain fatty acids (SCFAs), branched-chain fatty acids (BCFAs) and 16S rRNA sequencing were performed. Dietary assessment was performed with 7-day food diaries.

Sixty-one participants (31 females; median (IQR) age: 24.7 (23.0-27.8) years) were recruited. A dose-dependent impact of EN on faecal microbiota, SCFAs, BCFAs) and pH was observed, with changes detectable at EN intakes of at least 50% of energy requirements. 100% and 85% EN reduced the abundance of fibre-fermenting taxa such as Agathobacter, Faecalibaterium, Succinivibrio and Acidaminococcus. In parallel, potentially harmful organisms like Eubacterium, Actinomyces, and Klebsiella increased. In the 50% EN group, adherence to a diet high in fish, vegetables, potatoes, non-alcoholic beverages, and fat spreads, and low in cereal products, milk, and meat negatively correlated with changes in microbiota structure (r = -0.75, P = 0.025). This signal was not observed when using compositional tools for microbiota analysis.

EN detrimentally influences the faecal microbiota and diet-related bacterial metabolites in a dose-dependent manner, particularly at doses of at least 50%. The findings of this study have implications for the dietary management and counselling of patients receiving high volume EN.

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

This article provides a literature update on original articles published in the past 18 months (May 2022-November 2023) in the dietary management of paediatric Crohn's disease.

There is more data to support the use of exclusive enteral nutrition in the management of active Crohn's disease in children. Several food-based dietary therapies have been proposed for the management of Crohn's disease. There is an interest in precision nutritional therapy in Crohn's disease, but current data are scarce.

Exclusive enteral nutrition is an effective treatment for paediatric Crohn's disease. Predictors of response to exclusive enteral nutrition include mild disease phenotype and ileal disease involvement, although data remain inconclusive. Adherence to exclusive enteral nutrition is cornerstone to its efficacy. Treatment with exclusive enteral nutrition modifies the gut microbiome, modulates bile acid metabolism and has significant effects on host immune responses. More studies are expected in which drugs need to be combined with dietary therapies and microbial therapeutics. The efficacy of Crohn's disease exclusion diet coupled with partial enteral nutrition is supported by independent studies, but tolerance remains an issue, particularly for long-term disease management. More research is anticipated in precision nutritional therapy in paediatric Crohn's disease, but currently no recommendations can be made.

In pediatric Crohn's disease (CD), commercial formulas used as exclusive enteral nutrition (EEN) are effective at inducing remission. This study aims to assess the impact of a whole-food blended smoothie as EEN on CD activity and the intestinal microbiome.

A 4-week prospective trial assessed the impact of EEN with a whole-food smoothie on newly diagnosed mild-to-moderate active pediatric CD. The smoothie with a multivitamin were developed to meet age-appropriate nutritional requirements. Assessment over 4 weeks included Pediatric Crohn's Disease Activity Index (PCDAI), serum laboratories, fecal calprotectin (FCP), and stool collection for metagenomic shotgun sequencing and microbiota composition analysis. Clinical remission was defined as PCDAI ≤ 10 at week 4.

Ten participants were enrolled with median age 14.5 years, and 8 completed the trial. Baseline mean PCDAI was 26.3 ± 9.1 and mean FCP 1149 ± 718 µg/g. At week 4, 80% of participants achieved clinical remission. FCP decreased by over half in 60% of participants, with FCP below 250 µg/g in 60% and below 100 µg/g in 40%. Microbiome analysis showed a significant increase in species richness over 4 weeks (p = 0.01). Compared to baseline, the relative abundance at week 2 and at week 4 was significantly increased for Bifidobacterium and Streptococcus and decreased for Blautia (p < 0.05 for all).

A whole-food blended smoothie was effective for inducing clinical remission and decreasing FCP in pediatric CD similar to commercial EEN formulas. Further research may give insight into data-driven whole-food dietary approaches for CD management.

gov NCT03508193.

Inflammatory bowel diseases (IBDs) are chronic conditions characterized by periods of spontaneous intestinal inflammation and are increasing in industrialized populations. Combined with host genetics, diet and gut bacteria are thought to contribute prominently to IBDs, but mechanisms are still emerging. In mice lacking the IBD-associated cytokine, interleukin-10, we show that a fiber-deprived gut microbiota promotes the deterioration of colonic mucus, leading to lethal colitis. Inflammation starts with the expansion of natural killer cells and altered immunoglobulin-A coating of some bacteria. Lethal colitis is then driven by Th1 immune responses to increased activities of mucin-degrading bacteria that cause inflammation first in regions with thinner mucus. A fiber-free exclusive enteral nutrition diet also induces mucus erosion but inhibits inflammation by simultaneously increasing an anti-inflammatory bacterial metabolite, isobutyrate. Our findings underscore the importance of focusing on microbial functions-not taxa-contributing to IBDs and that some diet-mediated functions can oppose those that promote disease.

Predicting response to exclusive enteral nutrition (EEN) in active Crohn's disease (CD) could lead to therapy personalization and pretreatment optimization.

This study aimed to explore the ability of pretreatment parameters to predict fecal calprotectin (FCal) levels at EEN completion in a prospective study in children with CD.

In children with active CD, clinical parameters, dietary intake, cytokines, inflammation-related blood proteomics, and diet-related metabolites, metabolomics and microbiota in feces, were measured before initiation of 8 wk of EEN. Prediction of FCal levels at EEN completion was performed using machine learning. Data are presented with medians (IQR).

Of 37 patients recruited, 15 responded (FCal < 250 μg/g) to EEN (responders) and 22 did not (nonresponders). Clinical and immunological parameters were not associated with response to EEN. Responders had lesser (μmol/g) butyrate [responders: 13.2 (8.63-18.4) compared with nonresponders: 22.3 (12.0-32.0); P = 0.03], acetate [responders: 49.9 (46.4-68.4) compared with nonresponders: 70.4 (57.0-95.5); P = 0.027], phenylacetate [responders: 0.175 (0.013-0.611) compared with nonresponders: 0.943 (0.438-1.35); P = 0.021], and a higher microbiota richness [315 (269-347) compared with nonresponders: 243 (205-297); P = 0.015] in feces than nonresponders. Responders consumed (portions/1000 kcal/d) more confectionery products [responders: 0.55 (0.38-0.72) compared with nonresponders: 0.19 (0.01-0.38); P = 0.045]. A multicomponent model using fecal parameters, dietary data, and clinical and immunological parameters predicted response to EEN with 78% accuracy (sensitivity: 80%; specificity: 77%; positive predictive value: 71%; negative predictive value: 85%). Higher taxon abundance from Ruminococcaceae, Lachnospiraceae, and Bacteroides and phenylacetate, butyrate, and acetate were the most influential variables in predicting lack of response to EEN.

We identify microbial signals and diet-related metabolites in feces, which could comprise targets for pretreatment optimization and personalized nutritional therapy in pediatric CD.

Crohn's disease (CD) is an inflammatory bowel disease. Previous research has explored the impact of diet on CD, as specific dietary components can influence gut microbiota and immune responses, contributing to damage in the gastrointestinal tract. The Crohn's Disease Exclusion Diet (CDED) is based on an exclusion diet; it is a recent dietary approach that is often used alongside partial enteral nutrition (PEN) and aims to induce disease remission by excluding certain dietary components. This study assesses the current evidence for the effectiveness of the CDED + PEN in achieving remission in both children and adults with active CD. Our systematic review followed PRISMA recommendations and was registered in PROSPERO with CRD number 42022335076. The searched databases were PubMed/MEDLINE, Cochrane Library, Scopus, and Web of Science. The included studies were analyzed using Rayyan software, and the risk of bias was assessed with Cochrane RevMan 5.0 software. The primary assessed outcome was clinical remission, evaluated with validated questionnaire scores such as PCDAI, CDAI, or HBI. All analyzed papers yielded promising results. Notably, the CDED + PEN demonstrated better tolerance than exclusive enteral nutrition (EEN), resulting in higher adherence rates. Therefore, the CDED + PEN appears to be a viable alternative for induction remission in active disease for both children and adults with CD.

Patients with inflammatory bowel disease (IBD) often use the Internet to seek information beyond that received from healthcare professionals. This study assessed the perceptions of YouTube presenters on the role of diet in the management of IBD.

Videos discussing dietary aspects (food, diet-related items, and advisory comments [FODRIACs]) in the management of IBD were included. The perceptions of presenters toward each FODRIAC were labeled as positive, negative, or neutral/intermediate, and FODRIACs were classified according to their underlying role in the management of IBD (eg, symptom management, gut inflammation). Subgroup analysis was performed by type of video presenter (patients vs healthcare professionals), type of IBD (Crohn's disease vs ulcerative colitis), and reporting of scientific evidence supporting presenters' perceptions.

We identified 122 FODRIACs within 160 videos. Patient videos received a higher number of likes (median 85 [interquartile range, 35-156]) than healthcare professional videos (median 44 [interquartile range, 16-1440]) (P = .01). Scientific evidence was cited in 2 (3%) of 76 patient videos compared with 25 (35%) of 71 healthcare professional videos (P < .001). Positive perceptions were expressed about avocadoes, salmon, bananas, white bread, and rice, whereas negative perceptions were reported for processed, high-fat and high-sugar foods and carbonated drinks. Fewer negative perceptions were expressed in videos supported by scientific evidence than in videos that lacked evidence (scientific: 4 positive, 0 negative vs nonscientific: 7 positive, 20 negative; P = .01).

We have identified FODRIACs proposed as beneficial or detrimental in the management of IBD. The effect this information has on dietary practice as patients with IBD self-manage their condition needs further exploration.

There is demand from patients and clinicians to use the Crohn's disease exclusion diet (CDED) with or without partial enteral nutrition (PEN). However, the therapeutic efficacy and nutritional adequacy of this therapy are rudimentary in an adult population. This review examines the evidence for the CDED in adults with active luminal Crohn's disease and aims to provide practical guidance on the use of the CDED in Australian adults. A working group of nine inflammatory bowel disease (IBD) dietitians of DECCAN (Dietitians Crohn's and Colitis Australian Network) and an IBD gastroenterologist was established. A literature review was undertaken to examine (1) clinical indications, (2) monitoring, (3) dietary adequacy, (4) guidance for remission phase, and (5) diet reintroduction after therapy. Each diet phase was compared with Australian reference ranges for food groups and micronutrients. CDED with PEN is nutritionally adequate for adults containing sufficient energy and protein and meeting > 80% of the recommended daily intake of key micronutrients. An optimal care pathway for the clinical use of the CDED in an adult population was developed with accompanying consensus statements, clinician toolkit, and patient education brochure. Recommendations for weaning from the CDED to the Australian dietary guidelines were developed. The CDED + PEN provides an alternate partial food-based therapy for remission induction of active luminal Crohn's disease in an adult population. The CDED + PEN should be prioritized over CDED alone and prescribed by a specialist IBD dietitian. DECCAN cautions against using the maintenance diet beyond 12 weeks until further evidence becomes available.

Exclusive enteral nutrition (EEN) with fiber-free diets is an effective steroid-sparing treatment to induce clinical remission in children with Crohn's disease (CD). However, the mechanism underlying the beneficial effects of EEN remains obscure. Using a model of microbiota-dependent colitis with the hallmarks of CD, we find that the administration of a fiber-free diet prevents the development of colitis and inhibits intestinal inflammation in colitic animals. Remarkably, fiber-free diet alters the intestinal localization of Mucispirillum schaedleri, a mucus-dwelling pathobiont, which is required for triggering disease. Mechanistically, the absence of dietary fiber reduces nutrient availability and impairs the dissimilatory nitrate reduction to ammonia (DNRA) metabolic pathway of Mucispirillum, leading to its exclusion from the mucus layer and disease remission. Thus, appropriate localization of the specific pathobiont in the mucus layer is critical for disease development, which is disrupted by fiber exclusion. These results suggest strategies to treat CD by targeting the intestinal niche and metabolism of disease-causing microbes.

This scoping review provides an overview of publications reporting adverse effects on the intestines of the food additives carrageenan (CGN) (E 407)/processed Eucheuma seaweed (PES) (E 407a) and carboxymethylcellulose (CMC) (E 466). It includes evidence from human, experimental mammal and in vitro research publications, and other evidence. The databases Medline, Embase, Scopus, Web of Science Core Collection, Cochrane Database of Systematic Reviews and Epistemonikos were searched without time limits, in addition to grey literature. The publications retrieved were screened against predefined criteria. From two literature searches, 2572 records were screened, of which 224 records were included, as well as 38 records from grey literature, making a total of 262 included publications, 196 on CGN and 101 on CMC. These publications were coded and analyzed in Eppi-Reviewer and data gaps presented in interactive maps. For CGN, five, 69 and 33 research publications on humans, experimental mammals and in vitro experiments were found, further separated as degraded or native (non-degraded) CGN. For CMC, three human, 20 animal and 14 in vitro research publications were obtained. The most studied adverse effects on the intestines were for both additives inflammation, the gut microbiome, including fermentation, intestinal permeability, and cancer and metabolic effects, and immune effects for CGN. Further studies should focus on native CGN, in the form and molecular weight used as food additive. For both additives, randomized controlled trials of sufficient power and with realistic dietary exposure levels of single additives, performed in persons of all ages, including potentially vulnerable groups, are needed.

Inflammatory Bowel Disease (IBD) is a chronic, relapsing inflammatory disorder of the gastrointestinal tract. Though the pathogenesis of IBD remains unclear, diet is increasingly recognized as a pivotal factor influencing its onset and progression. Fatty acids, essential components of dietary lipids, play diverse roles in IBD, ranging from anti-inflammatory and immune-regulatory functions to gut-microbiota modulation and barrier maintenance. Short-chain fatty acids (SCFAs), products of indigestible dietary fiber fermentation by gut microbiota, have strong anti-inflammatory properties and are seen as key protective factors against IBD. Among long-chain fatty acids, saturated fatty acids, trans fatty acids, and ω-6 polyunsaturated fatty acids exhibit pro-inflammatory effects, while oleic acid and ω-3 polyunsaturated fatty acids display anti-inflammatory actions. Lipid mediators derived from polyunsaturated fatty acids serve as bioactive molecules, influencing immune cell functions and offering both pro-inflammatory and anti-inflammatory benefits. Recent research has also highlighted the potential of medium- and very long-chain fatty acids in modulating inflammation, mucosal barriers, and gut microbiota in IBD. Given these insights, dietary intervention and supplementation with short-chain fatty acids are emerging as potential therapeutic strategies for IBD. This review elucidates the impact of various fatty acids and lipid mediators on IBD and delves into potential therapeutic avenues stemming from these compounds.

Inflammatory bowel disease (IBD) is a chronic condition characterized by periods of spontaneous intestinal inflammation and is increasing in industrialized populations. Combined with host genetic predisposition, diet and gut bacteria are thought to be prominent features contributing to IBD, but little is known about the precise mechanisms involved. Here, we show that low dietary fiber promotes bacterial erosion of protective colonic mucus, leading to lethal colitis in mice lacking the IBD-associated cytokine, interleukin-10. Diet-induced inflammation is driven by mucin-degrading bacteria-mediated Th1 immune responses and is preceded by expansion of natural killer T cells and reduced immunoglobulin A coating of some bacteria. Surprisingly, an exclusive enteral nutrition diet, also lacking dietary fiber, reduced disease by increasing bacterial production of isobutyrate, which is dependent on the presence of a specific bacterial species, Eubacterium rectale. Our results illuminate a mechanistic framework using gnotobiotic mice to unravel the complex web of diet, host and microbial factors that influence IBD.

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

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

Pediatric inflammatory bowel disease (PIBD) is rising rapidly in many industrialised and affluent areas in the Asia Pacific region. Current available guidelines, mainly from Europe and North America, may not be completely applicable to clinicians caring for children with PIBD in this region due to differences in disease characteristics and regional resources constraints. This position paper is an initiative from the Asian Pan-Pacific Society for Pediatric Gastroenterology, Hepatology and Nutrition (APPSPGHAN) with the aim of providing an up-to-date, evidence-based approach to PIBD in the Asia Pacific region, taking into consideration the unique disease characteristics and financial resources available in this region. A group of pediatric gastroenterologists with special interest in PIBD performed an extensive literature search covering epidemiology, disease characteristics and natural history, management and monitoring. Gastrointestinal infections, including tuberculosis, need to be excluded before diagnosing IBD. In some populations in Asia, the Nudix Hydrolase 15 (NUD15) gene is a better predictor of leukopenia induced by azathioprine than thiopurine-S-methyltransferase (TPMT). The main considerations in the use of biologics in the Asia Pacific region are high cost, ease of access, and potential infectious risk, especially tuberculosis. Conclusion: This position paper provides a useful guide to clinicians in the medical management of children with PIBD in the Asia Pacific region.

Exclusive enteral nutrition (EEN) is the recommended induction treatment of mild to moderate active pediatric Crohn's disease (CD). This study compared outcomes of 2 proprietary polymeric formulas. Treatment effectiveness was examined along with practical aspects of formula delivery and differences in estimated treatment costs.

Data were retrospectively collected from patients with CD who received a generic oral nutritional supplement (Fortisip) across 2 centers (RCH, Melbourne and RHSC, Edinburgh). This was compared with a prospective cohort (RHC, Glasgow) that used a specialized formula (Modulen IBD). The data collected included patient demographics, remission rates, biochemical markers, administration method, and anthropometrics. The estimated treatment cost was performed by comparing price per kcal between each formula.

One hundred seventy-one patients were included (106 Fortisip, 65 Modulen IBD, 70 female; median age 13.3 yrs). No difference was demonstrated in remission rate (Fortisip n = 67 of 106 [63%] vs Modulen IBD n = 41 of 64 [64%], P = .89), nonadherence rate (Fortisip n = 7 of 106 [7%] vs Modulen IBD 3 of 64 [5%], P = .57) or method of administration (NGT Fortisip use n = 16 of 106 [12%] vs Modulen IBD 14 of 65 [22%]; P = .31). There was no difference in reduction of biochemical disease markers between the groups (C-reactive protein , P = .13; erythrocyte sedimentation rate, P = .49; fecal calprotectin, P = .94). However, there was a cost-saving of around £500/patient/course if the generic oral nutritional supplement was used.

The generic oral nutritional supplement and specialized formulas both had similar clinical effectiveness in induction of remission in pediatric CD. However, there is considerable cost-saving when using a generic oral nutritional supplement.

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

Historically, dietitians played a minor part in the management of inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis. Patients were commonly referred for consequences of uncontrolled disease, such as malnutrition and bowel obstruction risk. Today, dietitians are fundamental members of the multidisciplinary IBD team, from educating on the role of diet at diagnosis and throughout the lifespan of a patient with IBD to guiding primary induction therapy. This aspect is reflected in published guidelines for IBD management, which previously placed diet as only a minor factor, but now have diet-specific publications. This Review describes a four-step approach in a dietitian's assessment and management of diet in patients with IBD: (1) identifying and correcting nutritional gaps and dietary imbalances; (2) considering diet to treat active disease with the use of exclusive enteral nutrition (EEN) or emerging diets that could replace EEN; (3) using therapeutic diets to control existing complications of IBD, such as reduced fibre to prevent bowel obstruction in stricturing disease or a fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet to manage co-existing functional gut symptoms; and (4) considering the role of diet in preventing IBD development in high-risk populations.

From consumption of fermented foods and probiotics to emerging applications of faecal microbiota transplantation, the health benefit of manipulating the human microbiota has been exploited for millennia. Despite this history, recent technological advances are unlocking the capacity for targeted microbial manipulation as a novel therapeutic.

This review summarises the current developments in microbiome-based medicines and provides insight into the next steps required for therapeutic development.

Here we review current and emerging approaches and assess the capabilities and weaknesses of these technologies to provide safe and effective clinical interventions. Key literature was identified through Pubmed searches with the following key words, 'microbiome', 'microbiome biomarkers', 'probiotics', 'prebiotics', 'synbiotics', 'faecal microbiota transplant', 'live biotherapeutics', 'microbiome mimetics' and 'postbiotics'.

Improved understanding of the human microbiome and recent technological advances provide an opportunity to develop a new generation of therapies. These therapies will range from dietary interventions, prebiotic supplementations, single probiotic bacterial strains, human donor-derived faecal microbiota transplants, rationally selected combinations of bacterial strains as live biotherapeutics, and the beneficial products or effects produced by bacterial strains, termed microbiome mimetics.

Although methods to identify and refine these therapeutics are continually advancing, the rapid emergence of these new approaches necessitates accepted technological and ethical frameworks for measurement, testing, laboratory practices and clinical translation.