Impact of Environmental and Familial Factors in a Cohort of Pediatric Patients With Inflammatory Bowel Disease

Objectives: The primary role of environment on inflammatory bowel disease (IBD) onset has been recently stressed. We aimed to investigate the effect of environmental factors in an IBD pediatric cohort. Methods: A total of 467 subjects (264 IBD and 203 controls) were enrolled. All patients underwent a questionnaire including 5 different groups of environmental risk factors: family history of IBD and autoimmune diseases, perinatal period, home amenities and domestic hygiene, childhood diseases and vaccinations, and diet. Results: In a multivariate model, mother's degree (odds ratio [OR]: 5.5; 2.5-11.6), duration of breast feeding >3rd month (OR: 4.3; 1.6-10.5), father's employment (OR: 3.7; 1.2-8.7), gluten introduction <6th month (OR: 2.8; 1.5-5), number of siblings <2 (OR: 2.8; 1.5-5.3), and family history of autoimmune diseases (OR: 2.7; 1.4-5.3) were significant risk factors for Crohn disease. Low adherence to Mediterranean diet (OR: 2.3; 1.2-4.5), gluten introduction <6th month (OR: 2.8; 1.6-4.9), and number of siblings <2 (OR: 2; 1.1-3.6) were significant risk factors for ulcerative colitis. Owning pets (OR: 0.3; 0.1-0.7) and bed sharing (OR: 0.2; 0.1-0.6) were protective factors for Crohn disease, whereas owning pets (OR: 0.4; 0.2-0.8) and family parasitosis (OR: 0.07; 0.01-0.4) were protective factors for ulcerative colitis. Conclusions: Our study confirms that environmental factors are closely linked to IBD onset and may partly explain IBD rise in developed countries.