Impaired Epithelial CD200L Tolerance Signaling in Irritable Bowel Syndrome Cases With Diarrhea May Be Associated With Recurrent Miscarriages.

PROBLEM: There is a higher incidence of irritable bowel syndrome with miscarriages, and recurrent miscarriages of otherwise normal embryos have been linked to subnormal expression of the immune checkpoint inhibitor CD200L. We sought to determine if alterations in the expression of the CD200 immune checkpoint inhibitor occur in colonic tissue in IBS-D patients. METHOD OF STUDY: Quantitative immunohistochemical staining of biopsies from proximal and distal colon or rectum for the inhibitory CD200L and CD200S molecules was done. CD56 cells were also enumerated as they play a role in recurrent miscarriages and may express CD200S. RESULTS: CD200L was decreased and CD200S was unchanged in epithelium but not stroma of 3 IBS-D cases. One case had an increase in both CD200L and CD200S. CD56 cells were also stained for CD200S. Degranulation was assessed by the percentage of extracellular CD200S that was increased as epithelial CD200L decreased. CONCLUSIONS: This pilot study was promising and warrants a larger sample to determine if a correlation between uterine implantation site CD200L and CD200S expression in normal and failing implantation sites is needed. Colonic epithelial CD200L may then provide useful information about the pathogenesis of the spontaneous miscarriage in individual cases.

Incidence and predictors of major gastrointestinal bleeding in patients on aspirin, low-dose rivaroxaban, or the combination: Secondary analysis of the COMPASS randomised controlled trial.

BACKGROUND: The incidence of major gastrointestinal bleeding (GIB) in patients on low-dose direct-acting oral anticoagulants (DOACs) is relatively unknown. Estimates from randomised controlled trials (RCTs) are lacking. AIMS: To assess GIB incidence and predictors from RCT data of patients on aspirin, low-dose rivaroxaban, or both. METHODS: This was a secondary analysis of RCT data wherein patients received aspirin 100 mg daily and rivaroxaban 2.5 mg b.d., aspirin alone, or rivaroxaban 5 mg b.d. Patients were followed from 2013 to 2016 at 602 centres. Outcomes included overall, upper, and lower GIB. We employed multivariable logistic regression to yield odds ratios (ORs) and 95% confidence intervals for potential exposures. RESULTS: Among 27,395 patients, the annual incidence of GIB on rivaroxaban 2.5 mg b.d. with aspirin was 801.7 per 100,000 compared with 372.3 in 100,000 for aspirin. Age (OR 4.16, 2.53-6.82 for ≥75 vs. 55-64), peptic ulcer disease (PUD, OR 1.57, 1.01-2.44), liver disease (OR 2.09, 1.01-4.33), hypertension (OR 1.42, 1.04-1.94), and smoking (OR 1.85, 1.26-2.73) were associated with overall GIB. Kidney disease (OR 1.68, 1.12-2.51) was significantly associated with upper GIB, whereas diverticular disease (OR 3.75, 1.88-7.49) was associated with lower GIB. Addition of rivaroxaban to aspirin was associated more with lower GIB (OR 2.82, 1.64-4.84) than upper GIB (OR 1.86, 1.18-2.92). CONCLUSIONS: We established incidences and identified risk factors for GIB in users of low-dose DOACs. Novel risk factors included current or former smoking and diverticulosis. Future studies should aim to validate these risk factors.

Critical appraisal of the SIBO hypothesis and breath testing: A clinical practice update endorsed by the European society of neurogastroenterology and motility (ESNM) and the American neurogastroenterology and motility society (ANMS).

BACKGROUND: There is compelling evidence that microbe-host interactions in the intestinal tract underlie many human disorders, including disorders of gut-brain interactions (previously termed functional bowel disorders), such as irritable bowel syndrome (IBS). Small intestinal bacterial overgrowth (SIBO) has been recognized for over a century in patients with predisposing conditions causing intestinal stasis, such as surgical alteration of the small bowel or chronic diseases, including scleroderma and is associated with diarrhea and signs of malabsorption. Over 20 years ago, it was hypothesized that increased numbers of small intestine bacteria might also account for symptoms in the absence of malabsorption in IBS and related disorders. This SIBO-IBS hypothesis stimulated significant research and helped focus the profession's attention on the importance of microbe-host interactions as a potential pathophysiological mechanism in IBS. PURPOSE: However, after two decades, this hypothesis remains unproven. Moreover, it has led to serious unintended consequences, namely the widespread use of unreliable and unvalidated breath tests as a diagnostic test for SIBO and a resultant injudicious use of antibiotics. In this review, we examine why the SIBO hypothesis remains unproven and, given the unintended consequences, discuss why it is time to reject this hypothesis and its reliance on breath testing. We also examine recent IBS studies of bacterial communities in the GI tract, their composition and functions, and their interactions with the host. While these studies provide important insights to guide future research, they highlight the need for further mechanistic studies of microbe-host interactions in IBS patients before we can understand their possible role in diagnosis and treatment of patient with IBS and related disorders.

Effect of Brain-Gut Behavioral Treatments on Abdominal Pain in Irritable Bowel Syndrome: Systematic Review and Network Meta-Analysis.

BACKGROUND & AIMS: Some brain-gut behavioral treatments (BGBTs) are beneficial for global symptoms in irritable bowel syndrome (IBS). United States management guidelines suggest their use in patients with persistent abdominal pain, but their specific effect on this symptom has not been assessed systematically. METHODS: We searched the literature through December 16, 2023, for randomized controlled trials (RCTs) assessing efficacy of BGBTs for adults with IBS, compared with each other or a control intervention. Trials provided an assessment of abdominal pain resolution or improvement at treatment completion. We extracted data as intention-to-treat analyses, assuming dropouts to be treatment failures and reporting pooled relative risks (RRs) of abdominal pain not improving with 95% confidence intervals (CIs), ranking therapies according to the P score. RESULTS: We identified 42 eligible randomized controlled trials comprising 5220 participants. After treatment completion, the BGBTs with the largest numbers of trials and patients recruited demonstrating efficacy for abdominal pain, specifically, included self-guided/minimal contact cognitive behavioral therapy (CBT) (RR, 0.71; 95% CI, 0.54-0.95; P score, 0.58), face-to-face multicomponent behavioral therapy (RR, 0.72; 95% CI, 0.54-0.97; P score, 0.56), and face-to-face gut-directed hypnotherapy (RR, 0.77; 95% CI, 0.61-0.96; P score, 0.49). Among trials recruiting only patients with refractory global IBS symptoms, group CBT was more efficacious than routine care for abdominal pain, but no other significant differences were detected. No trials were low risk of bias across all domains, and there was evidence of funnel plot asymmetry. CONCLUSIONS: Several BGBTs, including self-guided/minimal contact CBT, face-to-face multicomponent behavioral therapy, and face-to-face gut-directed hypnotherapy may be efficacious for abdominal pain in IBS, although none was superior to another.

Environmental Factors Associated with Risk of Crohn's Disease Development in the Crohn's and Colitis Canada - Genetic, Environmental, Microbial Project.

BACKGROUND & AIMS: To date, it is unclear how environmental factors influence Crohn's disease (CD) risk and how they interact with biological processes. This study investigates the association between environmental exposures and CD risk and evaluates their association with pre-disease biomarkers. METHODS: We studied 4289 healthy first-degree relatives (FDRs) of patients with CD from the Crohn's and Colitis Canada - Genetic, Environmental, Microbial (CCC-GEM) project. Regression models identified environmental factors associated with future CD onset and their association with pre-disease biological factors, including altered intestinal permeability measured by urinary fractional excretion of lactulose to mannitol ratio (LMR); gut inflammation via fecal calprotectin (FCP) levels; and fecal microbiome composition through 16S rRNA sequencing. RESULTS: Over a 5.62-year median follow-up, 86 FDRs developed CD. Living with a dog between ages 5 and 15 (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.40-0.96; P = .034), and living with a large family size in the first year of life (HR, 0.43; 95% CI, 0.21-0.85; P = .016) were associated with decreased CD risk, whereas having a bird at the time of recruitment (HR, 2.78; 95% CI, 1.36-5.68; P = .005) was associated with an increased CD risk. Furthermore, living with a dog was associated with reduced LMR, altered relative abundance of multiple bacterial genera, and increased Chao1 diversity, whereas bird owners had higher FCP levels. Large family during participants' first year of life was associated with altered microbiota composition without affecting FCP or LMR. CONCLUSION: This study identifies environmental variables associated with CD risk. These variables were also associated with altered barrier function, subclinical inflammation, and gut microbiome composition shifts, suggesting potential roles in CD pathogenesis.

Measuring the Impact of Patient Engagement in Health Research: An Exploratory Study Using Multiple Survey Tools.

Background: Studies report various ways in which patients are involved in research design and conduct. Limited studies explore the influence of patient engagement (PE) at each research stage in qualitative research from the perspectives of all stakeholders. Methods: We established two small research groups, a Patient Researcher-Led Group and an Academic Researcher-Led Group. We recruited patient research partners (PRP; n = 5), researchers (n = 5), and clinicians (n = 4) to design and conduct qualitative research aimed at identifying candidate attributes related to patient preferences for tapering biologic treatments in inflammatory bowel disease. We administered surveys before starting, two months into, and post-project work. The surveys contained items from three PE evaluation tools. We assessed the two groups regarding the influence and impact each stakeholder had during the different research stages. Results: PRPs had a moderate or a great deal of influence on the critical research activities across the research stages. They indicated moderate/very/extremely meaningful engagement and agreed/strongly agreed impact of PE. PRPs helped operationalize the research question; design the study and approach; develop study materials; recruit participants; and collect and interpret the data. Conclusion: The three tools together provide deeper insight into the influence of PE at each research stage. Lessons learnt from this study suggest that PE can impact many aspects of research including the design, process, and approach in the context of qualitative research, increasing the patient-centeredness of the study. More comprehensive validated tools are required that work with a more diverse subject pool and in other contexts.

Studying How Patient Engagement Influences Research: A Mixed Methods Study.

BACKGROUND: There is evidence supporting the value of patient engagement (PE) in research to patients and researchers. However, there is little research evidence on the influence of PE throughout the entire research process as well as the outcomes of research engagement. The purpose of our study is to add to this evidence. METHODS: We used a convergent mixed method design to guide the integration of our survey data and observation data to assess the influence of PE in two groups, comprising patient research partners (PRPs), clinicians, and researchers. A PRP led one group (PLG) and an academic researcher led the other (RLG). Both groups were given the same research question and tasked to design and conduct an inflammatory bowel disease (IBD)-related patient preference study. We administered validated evaluation tools at three points and observed PE in the two groups conducting the IBD study. RESULTS: PRPs in both groups took on many operational roles and influenced all stages of the IBD-related qualitative study: launch, design, implementation, and knowledge translation. PRPs provided more clarity on the study design, target population, inclusion-exclusion criteria, data collection approach, and the results. PRPs helped operationalize the project question, develop study material and data collection instruments, collect data, and present the data in a relevant and understandable manner to the patient community. The synergy of collaborative partnership resulted in two projects that were patient-centered, meaningful, understandable, legitimate, rigorous, adaptable, feasible, ethical and transparent, timely, and sustainable. CONCLUSION: Collaborative and meaningful engagement of patients and researchers can influence all stages of qualitative research including design and approach, and outputs.

Patient preferences for active ulcerative colitis treatments and fecal microbiota transplantation.

Background: Fecal microbiota transplantation (FMT) is a promising treatment for active ulcerative colitis (UC). Understanding patient preferences can identify treatment features that may impact treatment decisions, improve shared decision-making, and contribute to patient-centered care, which is especially important in the context of novel treatments like FMT. Objectives: We aimed to quantify preferences for active UC treatments, specifically FMT and biologics, and identify patient characteristics associated with different preference patterns. Design: This is a cross-sectional survey study. Methods: We administered a discrete choice experiment (DCE) survey to elicit preferences in a sample of Canadian adults with UC. DCE data were analyzed using a main-effects mixed logit model and used to predict uptake of hypothetical scenarios reflecting alternative combinations of treatment features. Latent class modeling identified heterogeneity in patient preference patterns. Results: Participants' (n = 201) mean age was 47.1 years (SD: 14.5 years), 58% were female, and most (84%) had at least some post-secondary education. Almost half were willing to undergo FMT. When considering treatments for active UC, the most important attributes were chance of remission and severity of rare unknown side effects. All else equal, participants were most likely to uptake treatment that involves oral capsules/pills. Participants in the class with the highest utility for chance of remission were younger, had more severe disease, and 58% indicated that they would be willing to undergo FMT. Conclusion: We identified characteristics of UC patients who are more likely to be interested in FMT using preference elicitation methods. Patient-centered care can be enhanced by knowing which patients are more likely to be interested in FMT, potentially improving satisfaction with and adherence to treatments for active UC to maximize the effectiveness of treatment while considering heterogeneity in patient preferences.

Background and aims: Fecal microbiota transplantation (FMT) is a promising new treatment for active ulcerative colitis. Questions remain around the benefits and risks of FMT treatment for patients with ulcerative colitis. Understanding how patients weigh the treatment features and how treatment features influence their decisions may improve shared decision-making and contribute to patient-centered care, which is especially important for novel treatments like FMT.Using an experimentally designed survey, we aimed to:1. Elicit patient preferences for features of active ulcerative colitis treatments, specifically FMT and biologics; and,2. Identify patient characteristics associated with different preference patterns. Results: We found that younger patients with more severe disease are more likely to try FMT for the treatment of active ulcerative colitis. Oral capsules/pills are the preferred mode of treatment administration. Conclusions: These findings can enhance patient-centered care by characterizing patients who are more likely to be interested in FMT. Aligning treatment with the features that are important to patients can potentially improve satisfaction with and adherence to treatments for active ulcerative colitis to maximize their effectiveness for individual patients.

Patient preferences for active ulcerative colitis treatments and fecal microbiota transplantation.

Crohn's Disease Phenotypes and Associations With Comorbidities, Surgery Risk, Medications and Nonmedication Approaches: The MAGIC in IMAGINE Study.

BACKGROUND: We aimed to establish a cohort of persons with Crohn's disease (CD) enrolled from 14 Canadian centers to describe the contemporary presentation of CD in Canada. METHODS: All enrollees were at least 18 years old and underwent chart review for phenotype documentation by Montreal Classification at time of enrollment, comorbidities, inflammatory bowel disease (IBD) and other surgeries, and use IBD and other therapies. RESULTS: Of 2112 adults, 59% were female, and the mean age was 44.1 (+/-14.9SD) years. The phenotype distribution was B1 = 50.4%, B2 = 22.4%, B3 = 17.3%, and missing information = 9.9%. Perineal disease was present in 14.2%. Pertaining to disease location, 35.2% of patients had disease in L1, 16.8% in L2, 48% in L3, and 0.4% in L4. There was no difference in phenotype by gender, anxiety score, depression score. Disease duration was significantly different depending on disease behavior type (B1 = 12.2 ±â€…10.1; B2 = 19.4 ±â€…12.9; B3 = 18.9 ±â€…11.8, P < .0001). Isolated colonic disease was much less likely to be fibrostenotic or penetrating than inflammatory disease. Penetrating disease was more likely to be associated with ileocolonic location than other locations. Perineal disease was most commonly seen in persons with B3 disease behavior (24%) than other behaviors (11% B1; 20% B2 disease, P < .0001) and more likely to be seen in ileocolonic disease (L3;19%) vs L2 (17%) and L1 (11%; P < .0001). Surgery related to IBD occurred across each behavior types at the following rates: B1 = 23%, B2 = 64%, and B3 = 74%. Inflammatory bowel disease-related surgery rates by location of disease were L1 = 48%, L2 = 21%, and L3 = 51%. CONCLUSIONS: In exploring this large contemporary CD cohort we have determined that inflammatory disease is the main CD phenotype in Canada and that CD-related surgery remains very common.

Interactive training with a novel simulation model for upper gastrointestinal endoscopic hemostasis improves trainee technique and confidence.

Background and study aims Endoscopic hemostasis is a life-saving procedure for gastrointestinal bleeding; however, training for it is often performed on real patients and during urgent situations that put patients at risk. Reports of simulation-based training models for endoscopic hemostasis are scarce. Herein, we developed a novel simulator called "Medical Rising STAR-Ulcer type" to practice endoscopic hemostasis with hemoclips and coagulation graspers. This study aimed to evaluate the reproducibility of the clinical difficulty of this model and the effectiveness of simulation-based training for clipping hemostasis. Patients and methods This was a prospective educational study. Fifty gastroenterology residents from Japan and Canada were recruited to participate in a simulation-based training program. The primary outcome was the success rate for clipping hemostasis. We measured differences in trainee subjective assessment scores and evaluated the co-occurrence network based on comments after training. Results The hemostasis success rate of the trainees significantly increased after instruction (64% vs. 86%, P < 0.05). The success rate for ulcers in the upper body of the stomach (59%), a high-difficulty site, was significantly lower than that for ulcers in the antrum, even after feedback and instruction. Trainee self-perceived proficiency and confidence significantly improved after simulation-based training ( P < 0.05). Co-occurrence network analysis showed that trainees valued a structured learning approach, acknowledged simulator limitations, and recognized the need for continuous skill refinement. Conclusions Our study demonstrates the potential of our simulation-based training model as a valuable tool for improving technical skills and confidence in trainees learning to perform endoscopic hemostasis.

Exploring the outcomes of research engagement using the observation method in an online setting.

OBJECTIVE: The objective of this study was to explore the outcomes of research engagement (patient engagement, PE) in the context of qualitative research. DESIGN: We observed engagement in two groups comprised of patients, clinicians and researchers tasked with conducting a qualitative preference exploration project in inflammatory bowel disease. One group was led by a patient research partner (PLG, partner led group) and the other by an academic researcher (RLG, researcher led group). A semistructured guide and a set of critical outcomes of research engagement were used as a framework to ground our analysis. SETTING: The study was conducted online. PARTICIPANTS: Patient research partners (n=5), researchers (n=5) and clinicians (n=4) participated in this study. MAIN OUTCOME MEASURES: Transcripts of meetings, descriptive and reflective observation data of engagement during meetings and email correspondence between group members were analysed to identify the outcomes of PE. RESULTS: Both projects were patient-centred, collaborative, meaningful, rigorous, adaptable, ethical, legitimate, understandable, feasible, timely and sustainable. Patient research partners (PRPs) in both groups wore dual hats as patients and researchers and influenced project decisions wearing both hats. They took on advisory and operational roles. Collaboration seemed easier in the PLG than in the RLG. The RLG PRPs spent more time than their counterparts in the PLG sharing their experience with biologics and helping their group identify a meaningful project question. A formal literature review informed the design, project materials and analysis in the RLG, while the formal review informed the project materials and analysis in the PLG. A PRP in the RLG and the PLG lead leveraged personal connections to facilitate recruitment. The outcomes of both projects were meaningful to all members of the groups. CONCLUSIONS: Our findings show that engagement of PRPs in research has a positive influence on the project design and delivery in the context of qualitative research in both the patient-led and researcher-led group.

Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Some probiotics may be beneficial in irritable bowel syndrome (IBS), but differences in species and strains used, as well as endpoints reported, have hampered attempts to make specific recommendations as to which should be preferred. We updated our previous meta-analysis examining this issue. METHODS: MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (up to March 2023). Randomized controlled trials (RCTs) recruiting adults with IBS, comparing probiotics with placebo were eligible. Dichotomous symptom data were pooled to obtain a relative risk of global symptoms, abdominal pain, or abdominal bloating or distension persisting after therapy, with a 95% confidence interval (CI). Continuous data were pooled using a standardized mean difference with a 95% CI. Adverse events data were also pooled. RESULTS: We identified 82 eligible trials, containing 10,332 patients. Only 24 RCTs were at low risk of bias across all domains. For global symptoms, there was moderate certainty in the evidence for a benefit of Escherichia strains, low certainty for Lactobacillus strains and Lactobacillus plantarum 299V, and very low certainty for combination probiotics, LacClean Gold S, Duolac 7s, and Bacillus strains. For abdominal pain, there was low certainty in the evidence for a benefit of Saccharomyces cerevisae I-3856 and Bifidobacterium strains, and very low certainty for combination probiotics, Lactobacillus, Saccharomyces, and Bacillus strains. For abdominal bloating or distension there was very low certainty in the evidence for a benefit of combination probiotics and Bacillus strains. The relative risk of experiencing any adverse event, in 55 trials, including more than 7000 patients, was not significantly higher with probiotics. CONCLUSIONS: Some combinations of probiotics or strains may be beneficial in IBS. However, certainty in the evidence for efficacy by GRADE criteria was low to very low across almost all of our analyses.

Head-to-Head Diagnostic Test Accuracy Meta-analysis of Colonoscopy and Fecal Immunochemical Test in Detecting Advanced Colon Neoplasia.

Background: Studies on the use of fecal immunochemical test (FIT) in colorectal screening have long assumed perfect accuracy for colonoscopy. No study to date has directly compared the diagnostic accuracy of colonoscopy and FIT to detect advanced neoplasia (AN) in a head-to-head diagnostic accuracy meta-analysis. Methods: A comprehensive electronic search was performed for a head-to-head comparison of FIT and colonoscopy using a third acceptable reference standard in asymptomatic adults. Cochrane methodology was used to perform a head-to-head diagnostic test accuracy (DTA) meta-analysis. Quality assessment tool for diagnostic accuracy studies-2 (QUADAS-2) was used to assess the risk of bias in included studies. Results: Two studies met the eligibility criteria. Overall sensitivity and specificity were 98.5 (95% CI 96.3-100%) and 100% (99.9-100%) for colonoscopy and 16.4% (10.3-22.6%) and 95.4% (94.3-96.4%) for FIT. Colonoscopy was significantly better than FIT (P < 0.0001). The positive and negative likelihood ratios (LRs) were 1.75 (1.57-1.96) and 0.03 (0.01-0.08) for colonoscopy and 3.02 (2.01-4.55) and 0.88 (0.82-0.95) for FIT, respectively. Conclusion: Colonoscopy provides significantly better diagnostic accuracy to detect AN compared with FIT (GRADE: ⨁⨁◯◯). Our study provided precise sensitivity and specificity of both colonoscopy and FIT and a revision in screening policies based on an updated cost-effectiveness analysis considering the results of the head-to-head analysis.

Hemorrhage From Left Hepatic Artery Pseudoaneurysm as a Complication of Acute Pancreatitis in a Patient With Fibromuscular Dysplasia.

Hepatic artery pseudoaneurysms are a rare complication of pancreatitis, and their rupture and bleeding cause high mortality. We present the case of a 76-year-old woman with fibromuscular dysplasia who developed a new left hepatic artery pseudoaneurysm within a week of her first episode of acute pancreatitis and later suffered an acute pseudoaneurysm bleed successfully treated with transcatheter coil embolization. To the best of our knowledge, this is the first case reported of a patient with fibromuscular dysplasia with pancreatitis-related pseudoaneurysm formation. One must consider pseudoaneurysms and associated bleeding as complications of acute pancreatitis because prompt recognition can lead to timely management.

Psychosocial factors associated with j-pouch surgery for patients with IBD: a scoping review.

BACKGROUND: Ulcerative colitis and Crohn's disease are subtypes of inflammatory bowel disease: a chronic condition of unclear etiology characterized by inflammation of the small and large intestine. Inflammatory bowel disease is managed with diet, medications, and surgeries, with the most common surgery, recommended to ulcerative colitis patients being j-pouch surgery. PURPOSE: To assess the current literature concerning psychosocial factors associated with j-pouch surgery for patients with inflammatory bowel disease. METHODS: A systematic scoping review of the empirical and grey literature was conducted for original research on j-pouch surgery and psychosocial variables. Eight databases were searched: Medline, PsychInfo, CINAHL, EBM Reviews, ProQuest Dissertations and Theses Global, ResearchGate, Prospero, and PrePubMed. RESULTS: Thirty-nine articles were identified. Many studies (n = 18) adopted a case-series design, and none examined psychosocial interventions. The most popular psychosocial variables assessed were quality of life (n = 34) and those associated with sexual health and functioning (n = 9). CONCLUSIONS: Despite being an established surgical procedure, little research has examined the psychosocial implications of j-pouch surgery. As such, clinicians lack a robust understanding of how this procedure affects patients' psychiatric and social status and adaptive abilities. There is a need for high-quality research utilizing validated measures and rigorous design methodologies with control populations.

Gut Microbiome Composition Is Associated With Future Onset of Crohn's Disease in Healthy First-Degree Relatives.

BACKGROUND & AIMS: The cause of Crohn's disease (CD) is unknown, but the current hypothesis is that microbial or environmental factors induce gut inflammation in genetically susceptible individuals, leading to chronic intestinal inflammation. Case-control studies of patients with CD have cataloged alterations in the gut microbiome composition; however, these studies fail to distinguish whether the altered gut microbiome composition is associated with initiation of CD or is the result of inflammation or drug treatment. METHODS: In this prospective cohort study, 3483 healthy first-degree relatives (FDRs) of patients with CD were recruited to identify the gut microbiome composition that precedes the onset of CD and to what extent this composition predicts the risk of developing CD. We applied a machine learning approach to the analysis of the gut microbiome composition (based on 16S ribosomal RNA sequencing) to define a microbial signature that associates with future development of CD. The performance of the model was assessed in an independent validation cohort. RESULTS: In the validation cohort, the microbiome risk score (MRS) model yielded a hazard ratio of 2.24 (95% confidence interval, 1.03-4.84; P = .04), using the median of the MRS from the discovery cohort as the threshold. The MRS demonstrated a temporal validity by capturing individuals that developed CD up to 5 years before disease onset (area under the curve > 0.65). The 5 most important taxa contributing to the MRS included Ruminococcus torques, Blautia, Colidextribacter, an uncultured genus-level group from Oscillospiraceae, and Roseburia. CONCLUSION: This study is the first to demonstrate that gut microbiome composition is associated with future onset of CD and suggests that gut microbiome is a contributor in the pathogenesis of CD.

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

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

Immune response and barrier dysfunction-related proteomic signatures in preclinical phase of Crohn's disease highlight earliest events of pathogenesis.

OBJECTIVE: The measure of serum proteome in the preclinical state of Crohn's disease (CD) may provide insight into biological pathways involved in CD pathogenesis. We aimed to assess associations of serum proteins with future CD onset and with other biomarkers predicting CD risk in a healthy at-risk cohort. DESIGN: In a nested case-control study within the Crohn's and Colitis Canada Genetics Environment Microbial Project (CCC-GEM) cohort, which prospectively follows healthy first-degree relatives (FDRs), subjects who developed CD (n=71) were matched with four FDRs remaining healthy (n=284). Using samples at recruitment, serum protein profiles using the Olink Proximity Extension Assay platform was assessed for association with future development of CD and with other baseline biomarkers as follows: serum antimicrobial antibodies (AS: positive antibody sum) (Prometheus); faecal calprotectin (FCP); gut barrier function using the fractional excretion of lactulose-to-mannitol ratio (LMR) assay. RESULTS: We identified 25 of 446 serum proteins significantly associated with future development of CD. C-X-C motif chemokine 9 (CXCL9) had the highest OR with future risk of CD (OR=2.07 per SD, 95% CI 1.58 to 2.73, q=7.9e-5), whereas matrix extracellular phosphoglycoprotein had the lowest OR (OR 0.44, 95% CI 0.29 to 0.66, q=0.02). Notably, CXCL9 was the only analyte significantly associated with all other CD-risk biomarkers with consistent direction of effect (FCP: OR=2.21; LMR: OR=1.67; AS: OR=1.59) (q<0.05 for all). CONCLUSION: We identified serum proteomic signatures associated with future CD development, reflecting potential early biological processes of immune and barrier dysfunction.

Working to Answer the Effectiveness of Nutrition in IBD: Still a Ways to Go.

ABSTRACT: The Specific Carbohydrate diet (SCD) is an exclusion diet widely popular among patients with IBD, which restricts carbohydrates and processed foods. Two recently concluded controlled studies PRODUCE (Personalized Research on Diet in Ulcerative Colitis (UC) and Crohn's Disease) and DINE-CD (The Diet to Induce Remission in Crohn's disease) confirm efficacy of SCD on symptom control but fail to demonstrate a sustained anti-inflammatory response. These dietary studies are a welcome addition to a poorly understood field of dietary management of IBD, we explore some practical challenges including trial designs, recruitment, and retention in long term dietary intervention studies. Future dietary intervention studies should, therefore, incorporate endoscopic end points to establish a true anti-inflammatory response to elimination diets, preferably with detailed multi-omics analysis to understand mechanism of action.