Inflammatory Bowel Diseases: Review of Known Environmental Protective and Risk Factors Involved

• Published in: Inflammatory bowel diseases Vol. 23; no. 9; pp. 1499 - 1509
• Main Authors: van der Sloot, Kimberley W J, Amini, Marzyeh, Peters, Vera, Dijkstra, Gerard, Alizadeh, Behrooz Z
• Format: Journal Article
• Language: English
• Published: United States 01.09.2017
• Subjects: Air Pollution - adverse effects; Anti-Bacterial Agents - adverse effects; Anti-Inflammatory Agents, Non-Steroidal - adverse effects; Breast Feeding; Cigarette Smoking - adverse effects; Colitis, Ulcerative - epidemiology; Colitis, Ulcerative - etiology; Colitis, Ulcerative - prevention & control; Contraceptives, Oral - adverse effects; Crohn Disease - epidemiology; Crohn Disease - etiology; Crohn Disease - prevention & control; Environment; Environmental Exposure - adverse effects; Europe - epidemiology; Female; Genetic Predisposition to Disease; Helicobacter Infections - complications; Humans; Incidence; Life Style; Male; Protective Factors; Risk Factors; United States - epidemiology; Vitamin D - therapeutic use; Vitamins - therapeutic use
• ISSN: 1078-0998; 1536-4844
• DOI: 10.1097/MIB.0000000000001217

Inflammatory bowel diseases consisting of Crohn's disease and ulcerative colitis are chronic inflammatory diseases of the gastrointestinal tract. In addition to genetic susceptibility and disturbances of the microbiome, environmental exposures forming the exposome play an important role. Starting at birth, the cumulative effect of different environmental exposures combined with a predetermined genetic susceptibility is thought to cause inflammatory bowel disease. All these environmental factors are part of a Western lifestyle, suiting the high incidence rates in Europe and the United States. Whereas receiving breastfeeding, evidence of a Helicobacter pylori infection and vitamin D are important protective factors in Crohn's disease as well as ulcerative colitis, increased hygiene, experiencing a bacterial gastroenteritis in the past, urban living surroundings, air pollution, the use of antibiotics, nonsteroidal anti-inflammatory drugs, and oral contraceptives are likely to be the most important risk factors for both diseases. Current cigarette smoking yields a divergent effect by protecting against ulcerative colitis but increasing risk of Crohn's disease, whereas former smoking increases chances of both diseases. This review gives a clear overview of the current state of knowledge concerning the exposome. Future studies should focus on measuring this exposome yielding the possibility of combining all involved factors to one exposome risk score and our knowledge on genetic susceptibility.