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.

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.

Urine and Serum Metabolomic Profiles Differ by Disease Activity in Pregnant Women With Inflammatory Bowel Diseases.

Background and Aims: Inflammatory bowel disease (IBD), inclusive of ulcerative colitis and Crohn's disease, are chronic inflammatory conditions that impact women of childbearing age. It has been previously shown that IBD is associated with altered metabolomic profiles, but whether metabolomic changes also affect pregnant patients with IBD is completely unknown. Methods: This was a prospective cohort study comprised of 48 pregnant women with IBD who were followed throughout preconception and pregnancy. IBD disease activity was measured using biochemical markers C-reactive protein or fecal calprotectin using enzyme-linked immunosorbent assay and clinical disease activity using Harvey-Bradshaw Index or partial Mayo scores. Serum and urine samples were collected from preconception, trimester 1, and trimester 2 and analyzed using nuclear magnetic resonance spectroscopy combined with metabolomics set enrichment analysis. Results: We identified a total of 24 urine metabolites and 17 serum metabolites which were altered by active disease across pregnancy. First trimester (T1) active disease-associated metabolites were enriched in "amino acid metabolism" and "fatty-acid ß-oxidation." The leading urine metabolites at T1 were trimethyl-N-oxide (TMAO), succinic acid, and 3-hydroxy-2-methylbutyric acid, and leading serum metabolites were TMAO, glucose, and acetic acid. Multivariate modeling using serum TMAO, glucose, and acetic acid predicts T1 disease activity and correlated with mode of delivery and infant weights at delivery. Moreover, cross-time point modeling using metabolomes predicted future disease flare-up during pregnancy. Conclusion: These results suggest select host metabolites may be able to discriminate and predict disease activity and are correlated with pregnancy outcomes at delivery. This warrants further validation of metabolomics to monitor IBD in pregnancy.