Metabolomics reveal distinct molecular pathways associated with future risk of Crohn's Disease.

Host - microbiome interactions are central to Crohn'sdisease (CD) pathogenesis; yet the early metabolic alterations that precededisease onset remain poorly defined. To explore preclinical metabolicsignatures of CD, we analyzed baseline serum metabolomic profiles in a nestedcase-control study within the Crohn's and Colitis Canada - Genetics, Environment, Microbiome (CCC-GEM) Project, a prospective cohort of 5,122 healthyfirst-degree relatives (FDRs) of CD patients. We included 78 individuals wholater developed CD and 311 matched FDRs who remained disease-free.

Fasting elicits gut microbiome signature changes that extend to type 1 diabetes patients.

The gut microbiome has been linked to the pathogenesis of type 1 diabetes (T1D), identifying it as a promising therapeutic target. Nutritional interventions, which are an effective way to modulate the gut microbiome, thus show potential to be applied as complementary therapies for T1D. One particular dietary intervention, prolonged therapeutic fasting, has been shown to ameliorate symptoms of several autoimmune diseases, while also modifying the gut microbiota composition of healthy populations.

Durability of Antibody Responses to SARS-CoV-2 Vaccination over 12 Months in Pediatric Inflammatory Bowel Disease.

Background/objectives: Severe acute respiratory syndrome (SARS-CoV-2) has had a profound global impact and continues to represent a health challenge worldwide. The durability of SARS-CoV-2 vaccine responses in pediatric inflammatory bowel disease (PIBD) patients receiving biologic therapies is unknown. This study aimed to quantify SARS-CoV-2 antibody responses post vaccination in these immunosuppressed patients over 12 months.

Nociceptor neurons suppress alveolar macrophage-induced Siglec-F neutrophil-mediated inflammation to protect against pulmonary fibrosis.

Pulmonary fibrosis results from persistent and pathological tissue repair, which is therapeutically challenging to attenuate and often fatal. The immune processes involved in fibrosis remain ill defined. Using a bleomycin-induced lung fibrosis murine model, we discovered that vagal TRPV1 nociceptors are protective.

Crosstalk with infant-derived Th17 cells, as well as exposure to IL-22 promotes maturation of intestinal epithelial cells in an enteroid model.

Introduction: The intestinal epithelium of human infants is developmentally immature compared to that of adults. Exactly how this immaturity affects key epithelial functions and their interactions with nearby immune cells remains an understudied area of research, partly due to limited access to non-diseased infant gut tissues. Human intestinal organoids, or "mini guts" generated from tissue stem cells, are promising models for investigating intestinal biology and disease mechanisms.

Neutrophil-to-Lymphocyte Ratio at Diagnosis Predicts Colonoscopic Activity in Pediatric Inflammatory Bowel Diseases.

Introduction: Neutrophil-to-lymphocyte ratio (NLR) is a novel biomarker studied in several autoimmune diseases including inflammatory bowel disease (IBD) in adults but poorly characterized in pediatric IBD (pIBD). We aimed to primarily investigate the relationship between NLR and pIBD endoscopic disease severity. We also examined whether NLR predicted hospitalization, surgery, and therapy response by 52 weeks.

Development of novel GI-centric prostaglandin E receptor type 4 (EP4) agonist prodrugs as treatment for ulcerative colitis and other intestinal inflammatory diseases.

Prostaglandin E receptor type 4 (EP4) agonists have been shown to be effective in treating experimental ulcerative colitis (UC) in animals and in human clinical trials, but their development has been impeded by unacceptable systemic side effects. In this study, a series of methylene phosphate prodrugs of a highly potent and selective prostaglandin EP4 receptor agonist were designed to target and remain localized in the gastrointestinal (GI) tract after either oral or rectal instillation. The prodrugs were designed to be converted to liberate active EP4 agonist by intestinal alkaline phosphate (IAP), a ubiquitous enzyme found at the luminal of the intestinal wall thus exposing the colon epithelial barrier while reducing systemic exposure to the active agonist.

Bolstering connectedness through peer support: Randomized-controlled trial of a web-based peer support program for adolescents with inflammatory bowel disease.

Background: Inflammatory bowel disease (IBD) is a chronic autoimmune disease often diagnosed during adolescence. IBD negatively impacts all aspects of health-related quality of life, resulting in physical, emotional, social, school, and work functioning challenges. Adolescents have identified the need for peer support in managing their disease and promoting positive health outcomes.

Healthy First-Degree Relatives From Multiplex Families vs Simplex Families Have Higher Subclinical Intestinal Inflammation, a Distinct Fecal Microbial Signature, and Harbor a Higher Risk of Developing Crohn's Disease.

Background & Aims: Unaffected first-degree relatives (FDRs) from families with ≥2 affected FDRs with Crohn's disease (CD, multiplex families) have a high risk of developing CD, although the underlying mechanisms driving this risk are poorly understood. We aimed to identify differences in biomarkers between FDRs from multiplex vs simplex families and investigate the risk of future CD onset accounting for potential confounders.

Methods: We assessed the Crohn's and Colitis Canada Genetic Environmental Microbial cohort of healthy FDRs of patients with CD.

The role of upper gastrointestinal endoscopy in the diagnosis of pediatric inflammatory bowel disease.

Objectives: Upper gastrointestinal (UGI) tract involvement is frequently reported in pediatric Crohn disease (CD) and ulcerative colitis (UC). Aside from granulomas, most findings are nonspecific. The aims of this study were to review the prevalence of UGI tract findings in pediatric patients with CD or UC at diagnosis and to describe differences in endoscopic and histologic features.

Landscape of TPMT and NUDT15 Pharmacogenetic Variation in a Cohort of Canadian Pediatric Inflammatory Bowel Disease Patients.

Background: Patients with inflammatory bowel disease (IBD) exhibit considerable interindividual variability in medication response, highlighting the need for precision medicine approaches to optimize and tailor treatment. Pharmacogenetics (PGx) offers the ability to individualize dosing by examining genetic factors underlying the metabolism of medications such as thiopurines. Pharmacogenetic testing can identify individuals who may be at risk for thiopurine dose-dependent adverse reactions including myelosuppression.

Pre-Diagnosis Diet Predicts Response to Exclusive Enteral Nutrition and Correlates with Microbiome in Pediatric Crohn Disease.

Exclusive enteral nutrition (EEN) is effective in inducing remission in pediatric Crohn disease (CD). EEN alters the intestinal microbiome, but precise mechanisms are unknown. We hypothesized that pre-diagnosis diet establishes a baseline gut microbiome, which then mediates response to EEN.

Variation in the Care of Children with Inflammatory Bowel Disease Within and Across Canadian Provinces: A Multi-Province Population-Based Cohort Study.

Purpose: The incidence of childhood-onset inflammatory bowel disease (IBD) is rising. We described variation in health services utilization and need for surgery among children with IBD between six and 60 months following IBD diagnosis across Canadian pediatric centers and evaluated the associations between care provided at diagnosis at each center and the variation in these outcomes.

Patients And Methods: Using population-based deterministically-linked health administrative data from four Canadian provinces (Alberta, Manitoba, Nova Scotia, Ontario) we identified children diagnosed with IBD <16 years of age using validated algorithms.

Health Services Utilization and Specialist Care in Pediatric Inflammatory Bowel Disease: A Multiprovince Population-Based Cohort Study.

Background: Patterns of health services utilization among children with inflammatory bowel disease (IBD) are important to understand as the number of children with IBD continues to increase. We compared health services utilization and surgery among children diagnosed <10 years of age (Paris classification: A1a) and between 10 and <16 years of age (A1b).

Methods: Incident cases of IBD diagnosed <16 years of age were identified using validated algorithms from deterministically linked health administrative data in 5 Canadian provinces (Alberta, Manitoba, Nova Scotia, Ontario, Quebec) to conduct a retrospective cohort study.

Insights Into Inflammatory Bowel Disease and Effects of Dietary Fatty Acid Intake With a Focus on Polyunsaturated Fatty Acids Using Preclinical Models.

While the aetiology of inflammatory bowel disease (IBD) has been linked to genetic susceptibility coupled with environmental factors, the underlying molecular mechanisms remain unclear. Among the environmental factors, diet and the gut microbiota have been implicated as drivers of immune dysregulation in IBD. Indeed, epidemiologic studies have highlighted that the increase in incidence of IBD parallels the increase in dietary intake of omega-6 (n-6) polyunsaturated fatty acids (PUFAs) and the change in balance of intake of n-6 to n-3 fatty acids.

User testing to modify the MyHealthyGut digital health application for inflammatory bowel disease.

Introduction: Inflammatory bowel disease, characterized by chronic intestinal inflammation, can be subcategorized into Crohn's disease and ulcerative colitis. The treatment for these conditions is unique to each patient and may include lifestyle changes, pharmaceutical intervention, and surgery. Lifestyle changes, such as dietary intervention, are a cornerstone of inflammatory bowel disease symptom management.

Outcomes Following Acute Severe Colitis at Initial Presentation: A Multi-centre, Prospective, Paediatric Cohort Study.

Aim: To assess contemporary outcomes in children with acute severe ulcerative colitis [ASUC] at initial presentation.

Methods: Between April 2014 and January 2019, children aged <17 years, with new onset ASUC (Paediatric Ulcerative Colitis Activity Index [PUCAI ≥65) were prospectively followed in a Canadian inception cohort study. 16S rRNA amplicon sequencing captured microbial composition of baseline faecal samples.

Spatial cluster mapping and environmental modeling in pediatric inflammatory bowel disease.

Background: Geographical (geospatial) clusters have been observed in inflammatory bowel disease (IBD) incidence and linked to environmental determinants of disease, but pediatric spatial patterns in North America are unknown. We hypothesized that we would identify geospatial clusters in the pediatric IBD (PIBD) population of British Columbia (BC), Canada and associate incidence with ethnicity and environmental exposures.

Aim: To identify PIBD clusters and model how spatial patterns are associated with population ethnicity and environmental exposures.

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.

A Mediterranean Diet Pattern Improves Intestinal Inflammation Concomitant with Reshaping of the Bacteriome in Ulcerative Colitis: A Randomised Controlled Trial.

Background And Aims: Dietary patterns are important in managing ulcerative colitis [UC], given their influence on gut microbiome-host symbiosis and inflammation. We investigated whether the Mediterranean Diet Pattern [MDP] vs the Canadian Habitual Diet Pattern [CHD] would affect disease activity, inflammation, and the gut microbiome in patients with quiescent UC.

Methods: We performed a prospective, randomised, controlled trial in adults [65% female; median age 47 years] with quiescent UC in an outpatient setting from 2017 to 2021.

Transition Readiness in Youth with Inflammatory Bowel Disease.

Objectives: To examine readiness of adolescents and young adults (AYAs) with inflammatory bowel disease (IBD) to transition to adult care.

Study Design: A cross-sectional multicenter study evaluating transition readiness in individuals with IBD 16-19 years old prospectively recruited from 8 Canadian IBD centers using the validated ON Taking Responsibility for Adolescent to Adult Care (ON TRAC) questionnaire. Secondary aims included (1) screening for depression and anxiety using the 8-item Personal Health Questionnaire Depression Scale and The Screen for Child Anxiety Related Emotional Disorders questionnaires, respectively; (2) evaluating the association between depression and anxiety with readiness and disease activity; and (3) subjectively evaluating AYA readiness based on physician and parent assessments.

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).