Take-home messages from 20 years progress in dietary therapy of inflammatory bowel disease

Background: A significant body of literature has interrogated the critical role of diet in the development and management of inflammatory bowel disease (IBD). Summary: This review provides a summary and critical appraisal of the literature in this area, focussing on four distinct themes: nutritional epidemiology, animal and in vitro experiments, enteral nutrition, and food-based dietary therapies. Key Messages: Nutritional epidemiology and data from experiments in animals indicate that a western-type diet pattern is associated with increased risk of IBD onset. However, these findings have not been consistently replicated in the dietary management of IBD. Exclusive enteral nutrition (EEN) is the only dietary therapy with reproducible evidence of efficacy in the management of active Crohn’s disease (CD). Use of EEN may also be useful for improving perioperative outcomes in CD, and as an adjuvant therapy to biologic therapy. Several dietary therapies for CD and ulcerative colitis have been proposed in the literature, but replication in well-controlled studies is needed before their routine use enters the clinical setting. Precision nutritional therapy might be an attractive therapeutic paradigm in a heterogenous disease like IBD. However, no recommendations for personalised dietary therapy can currently be made, and it is imperative we unravel the complex interplay between diet and gut inflammation before we are able to do so. Undoubtedly, diet is of critical importance in the development and management of IBD. However, the exact mechanism by which diet causes gut inflammation is still elusive, and dietary guidance is difficult to formulate.</p

Take-home messages from 20 years progress in dietary therapy of inflammatory bowel disease

Background: A significant body of literature has interrogated the critical role of diet in the development and management of inflammatory bowel disease (IBD). Summary: This review provides a summary and critical appraisal of the literature in this area, focussing on four distinct themes: nutritional epidemiology, animal and in vitro experiments, enteral nutrition, and food-based dietary therapies. Key Messages: Nutritional epidemiology and data from experiments in animals indicate that a western-type diet pattern is associated with increased risk of IBD onset. However, these findings have not been consistently replicated in the dietary management of IBD. Exclusive enteral nutrition (EEN) is the only dietary therapy with reproducible evidence of efficacy in the management of active Crohn’s disease (CD). Use of EEN may also be useful for improving perioperative outcomes in CD, and as an adjuvant therapy to biologic therapy. Several dietary therapies for CD and ulcerative colitis have been proposed in the literature, but replication in well-controlled studies is needed before their routine use enters the clinical setting. Precision nutritional therapy might be an attractive therapeutic paradigm in a heterogenous disease like IBD. However, no recommendations for personalised dietary therapy can currently be made, and it is imperative we unravel the complex interplay between diet and gut inflammation before we are able to do so. Undoubtedly, diet is of critical importance in the development and management of IBD. However, the exact mechanism by which diet causes gut inflammation is still elusive, and dietary guidance is difficult to formulate.</p

An automated identification and analysis of ontological terms in gastrointestinal diseases and nutrition-related literature provides useful insights

With an unprecedented growth in the biomedical literature, keeping up to date with the new developments presents an immense challenge. Publications are often studied in isolation of the established literature, with interpretation being subjective and often introducing human bias. With ontology-driven annotation of biomedical data gaining popularity in recent years and online databases offering metatags with rich textual information, it is now possible to automatically text-mine ontological terms and complement the laborious task of manual management, interpretation, and analysis of the accumulated literature with downstream statistical analysis. In this paper, we have formulated an automated workflow through which we have identified ontological information, including nutrition-related terms in PubMed abstracts (from 1991 to 2016) for two main types of Inflammatory Bowel Diseases: Crohn’s Disease and Ulcerative Colitis; and two other gastrointestinal (GI) diseases, namely, Coeliac Disease and Irritable Bowel Syndrome. Our analysis reveals unique clustering patterns as well as spatial and temporal trends inherent to the considered GI diseases in terms of literature that has been accumulated so far. Although automated interpretation cannot replace human judgement, the developed workflow shows promising results and can be a useful tool in systematic literature reviews. The workflow is available at https://github.com/KociOrges/pytag

Dietary treatment of Crohn’s disease: perceptions of families with children treated by exclusive enteral nutrition, a questionnaire survey

Background: Diet is strongly associated with the aetiology of Crohn’s Disease (CD) and exclusive enteral nutrition (EEN) is the primary induction treatment in paediatric CD. This study explored opinions around the use of EEN and alternative novel, solid food-based diets (SFDs) expressed by paediatric patients with CD, previously treated with EEN and their parents. Methods: This anonymous questionnaire surveyed families of CD patients treated with EEN over 1 year. Two questionnaire forms were completed; one asking the patients’ opinions and another referring to their main carer. This questionnaire explored participants’ demographic characteristics; acceptability of a repeat EEN course to treat a future flare (EEN repeat); their opinion on how difficult EEN would be compared to an example SFD; and their intention to participate in a future clinical trial assessing the therapeutic efficacy of an SFD in CD. Results: Forty-one families of CD patients were approached with 29 sending replies (71%). Most of our participants were positive on completing another EEN course, however the majority would choose an SFD alternative (Patients: 66, Parents:72%). Both patients and their parents rated EEN to be more difficult to adhere to compared to an example SFD (p &lt; 0.05), and their ratings were strongly correlated (EEN:r = 0.83, SFD:r = 0.75, p &lt; 0.001). The majority of our respondents would agree to participate in a clinical trial assessing an SFD’s effectiveness (Patients:79, Parents:72%) for the management of active CD. Conclusions: While patients with CD and their families would accept an EEN repeat, the majority would prefer an SFD alternative. CD families surveyed are supportive of the development of solid food-based dietary treatments

YouTube as a source of information for food, diet-related items, and advisory comments for the management of inflammatory bowel disease

Background: 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. Methods: 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. Results: 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 &lt; .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). Conclusions: 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

The distinct features of microbial 'dysbiosis' of Crohn's disease do not occur to the same extent in their unaffected, genetically linked kindred

Background/Aims: Studying the gut microbiota in unaffected relatives of people with Crohn’s disease (CD) may advance our understanding of the role of bacteria in disease aetiology. Methods: Faecal microbiota composition (16S rRNA gene sequencing), genetic functional capacity (shotgun metagenomics) and faecal short chain fatty acids (SCFA) were compared in unaffected adult relatives of CD children (CDR, n = 17) and adult healthy controls, unrelated to CD patients (HUC, n = 14). The microbiota characteristics of 19 CD children were used as a benchmark of CD ‘dysbiosis’. Results: The CDR microbiota was less diverse (p = 0.044) than that of the HUC group. Local contribution of β-diversity analysis showed no difference in community structure between the CDR and HUC groups. Twenty one of 1,243 (1.8%) operational taxonomic units discriminated CDR from HUC. The metagenomic functional capacity (p = 0.207) and SCFA concentration or pattern were similar between CDR and HUC (p&#62;0.05 for all SCFA). None of the KEGG metabolic pathways were different between these two groups. Both of these groups (HUC and CDR) had a higher microbiota α-diversity (CDR, p = 0.026 and HUC, p&#60;0.001) with a community structure (β-diversity) distinct from that of children with CD. Conclusions: While some alterations were observed, a distinct microbial ‘dysbiosis’, characteristic of CD patients, was not observed in their unaffected, genetically linked kindred

Development and Validation of the Glasgow Exclusive Enteral Nutrition Index of Compliance

Background and Aims: Treatment adherence is key to the efficacy of exclusive enteral nutrition [100% EN] in active Crohn’s disease [CD], but there are no biomarkers to objectively estimate this. We explored faecal parameters as biomarkers of compliance with 100% EN, and subsequently developed and validated the Glasgow Exclusive Enteral Nutrition Index of Compliance [GENIE]. Methods: Healthy adults replaced all [100% EN] or part [85% EN, 50% EN, 20% EN] of their diet with a formula for 7 days. Faecal pH, water content, short chain fatty acids, and branched chain fatty acids [BCFAs] were measured before [D0] and after [D7] each intervention. Optimal biomarkers and threshold values were derived using receiver operating characteristic curve analyses and machine learning to develop the GENIE. The GENIE was then validated in 30 CD children, during and after 100% EN. Results: In all, 61 adults were recruited. D7 faecal pH and the ratios of BCFAs to either acetate or butyrate performed the best to differentiate between patients on 100% EN from &lt;100% EN. Two models were generated; one included faecal metabolites (Laboratory GENIE, L-GENIE; sensitivity, specificity, and positive predictive value [PPV] of 88%, 94%, and 92%) and a second one [Clinical Genie, C-GENIE] which considers only faecal pH [sensitivity, specificity, and PPV of 84%, 86%, and 81%]. Validation of GENIE in CD children found that C-GENIE outperformed L-GENIE, producing a sensitivity, specificity, and PPV of 85%, 88%, and 88%, respectively. Conclusions: GENIE can help predict adherence to 100% EN and may complement current conventional dietary assessment.</p

Comparison of clinical methods with the faecal gluten immunogenic peptide to assess gluten intake in coeliac disease

Objectives: Detection of faecal gluten immunogenic peptides (GIP) is a biomarker of recent gluten consumption. GIP levels can be used to monitor gluten intake and compliment clinical methods to evaluate compliance to gluten free diet (GFD). In this study, recent gluten intake was measured by GIP in CD children and compared to routine clinical measures to evaluate GFD compliance. Methods: GIP was measured in 90 samples from 63 CD children (44 previously and 19 newly diagnosed with follow-up samples at 6 and 12 months on GFD). Compliance to GFD was evaluated based on clinical assessment, tTG levels and Biagi score. Results: GIP was detectable in 16% of patients with previous CD diagnosis on GFD. BMI z-score (p=0.774), height z-score (p=0.723), haemoglobin concentration (p=0.233), age (p=0.448), gender (p=0.734) or disease duration (p=0.488) did not differ between those with detectable and non-detectable GIP. In newly diagnosed patients, on gluten containing diet, GIP was detectable in 95% of them. Following GFD initiation, GIP decreased (p&lt;0.001); 17% and 27% had detectable levels at 6 and 12 months, respectively. Compared to GIP, the Biagi score, tTG and clinical assessment presented sensitivity of 17%, 42% and 17%. Likewise, GIP was detectable in 16%, 16%, 14% of patients evaluated as GFD compliant according to the Biagi score, tTG and clinical assessment. A combination of methods did not improve identification of patients who were non-compliant. Conclusions: Inclusion of faecal GIP measurements is likely to improve identification of GFD recent noncompliance in CD management and could be incorporated into current follow-up strategies

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An optimised monophasic faecal extraction method for LC-MS analysis and its application in gastrointestinal disease

Liquid chromatography coupled with mass spectrometry (LC-MS) metabolomic approaches are widely used to investigate underlying pathogenesis of gastrointestinal disease and mechanism of action of treatments. However, there is an unmet requirement to assess faecal metabolite extraction methods for large-scale metabolomics studies. Current methods often rely on biphasic extractions using harmful halogenated solvents, making automation and large-scale studies challenging. The present study reports an optimised monophasic faecal extraction protocol that is suitable for untargeted and targeted LC-MS analyses. The impact of several experimental parameters, including sample weight, extraction solvent, cellular disruption method, and sample-to-solvent ratio, were investigated. It is suggested that a 50 mg freeze-dried faecal sample should be used in a methanol extraction (1:20) using bead beating as the means of cell disruption. This is revealed by a significant increase in number of metabolites detected, improved signal intensity, and wide metabolic coverage given by each of the above extraction parameters. Finally, we addressed the applicability of the method on faecal samples from patients with Crohn’s disease (CD) and coeliac disease (CoD), two distinct chronic gastrointestinal diseases involving metabolic perturbations. Untargeted and targeted metabolomic analysis demonstrated the ability of the developed method to detect and stratify metabolites extracted from patient groups and healthy controls (HC), highlighting characteristic changes in the faecal metabolome according to disease. The method developed is, therefore, suitable for the analysis of patients with gastrointestinal disease and can be used to detect and distinguish differences in the metabolomes of CD, CoD, and HC