What environmental factors contribute to Crohns disease?
Environmental factors play a prominent role in the pathogenesis of inflammatory bowel disease (IBD), according to accumulating epidemiologic data. Such factors include behaviors that increase risk at an individual level, such as diet and those that affect entire populations, such as urbanization. Show
Subscribe to the latest updates from Digestive Health Advances in MotionThank you for subscribing! Error: Please enter a valid email address. Email Address Submit In Gastroenterology & Hepatology (NY), Amar Vedamurthy, MD, MS, hospitalist within the Department of Medicine at Massachusetts General Hospital, and Ashwin N. Ananthakrishnan, MBBS, MPH, director of the Mass General Crohn's and Colitis Center, recently reviewed the literature on environmental factors that influence the development and outcomes of Crohn's disease (CD) and ulcerative colitis (UC). SmokingGastroenterologists have known for decades that smoking influences the risk of IBD. Chronic smoke exposure can change immune responses and the composition of the gut microbiome, and it can predispose patients to intestinal inflammation by altering the composition and integrity of the epithelial mucous membrane. Both current and former smokers are at increased risk of CD. Current smokers with CD have increased need for medical therapy, surgery and second surgery, and they are at higher risk of disease flares including flares after surgery. In fascinating contrast, current smokers with UC have a milder disease course than nonsmokers, including less need for surgery. In fact, smoking cessation by patients with UC is frequently associated with relapse. DietDiet is considered an important environmental factor in the pathogenesis of IBD. For example:
Most patients diagnosed with IBD come to find that diet affects their symptoms. However, there is limited data on the ability of dietary modification to achieve sustained disease remission. AntibioticsThe use of antibiotics, which alters the gut microbiome, has been examined in multiple epidemiologic studies of IBD. For example:
Fecal microbiota transplantation and microbiome manipulation using antibiotics have shown promise in the treatment of IBD, but the data are still inadequate to support them as primary therapy. Geographic FactorsThe gap between Western and Eastern countries in the prevalence of IBD is narrowing, which is probably largely attributable to urbanization, westernization of diet and improvement in hygiene in Eastern countries. People living in urban areas have a higher incidence of IBD than those in rural areas. The oft-cited hygiene hypothesis may be explanatory: Urban settings have fewer influences, such as exposure to animals and pets, that protect against an immune response skewed toward autoimmunity and atopy. Northern latitudes are associated with a higher risk of IBD than southern latitudes, possibly because of low exposure to sunlight and consequent deficiency of vitamin D, which is known to modulate intestinal inflammation. Other FactorsThere are a multitude of additional factors that influence the development of CD and UC. For example:
Potential for Future ResearchThe latest research provides key insights into how environmental factors affect susceptibility to IBD, but few studies have examined whether modifying those factors changes the disease course. Continued research into environmental influences on IBD could lead to new strategies for disease prevention and treatment. view original journal article Subscription may be required Gastroenterology & Hepatology (NY) Journal Article Published: February 1, 2019 Visit the Crohn's and Colitis Center Contact the Digestive Healthcare Center Contributors Amar Vedamurthy, MBBS, MS ›Internist, Department of Medicine, Massachusetts General Hospital Ashwin N. Ananthakrishnan, MBBS, MPH ›Director of the Crohn's and Colitis Center, Division of Gastroenterology, Mass General, Associate Professor of Medicine, Harvard Medical School Related topics
Related Research Highlights Intestinal Dysbiosis as Defining Feature of Microscopic ColitisIntestinal dysbiosis appears to be the defining feature of the gut microbiome in microscopic colitis. Bowel Disease, Digestive Health Journal December 17, 2019 Related Electronic Health Records Can Be Used to Validate Genetic Determinants of Treatment Response in IBDFor patients with inflammatory bowel disease, narrative text in electronic health records was successfully used to validate associations between genetic risk scores and response to tumor necrosis factor inhibitors—a potential boon to identifying biomarkers of response to different drug classes. What environmental factors can cause Crohn's?Environmental Triggers. Diet (DINE-CD study) A clinical research study, sponsored by the Crohn's & Colitis Foundation and the Patient Centered Outcomes Research Institute (PCORI), to evaluate the effects of a nutrition-based intervention on patient outcomes. ... . Psychological Stress. ... . Viruses. ... . Smoke.. What are the 3 contributing factors of Crohn's disease?The disease can occur at any age, but Crohn's disease is most prevalent in adolescents and adults between the ages of 15 and 35. Diet and stress may aggravate Crohn's disease, but do not cause the disease. Recent research suggests hereditary, genetic, and environmental factors contribute to Crohn's disease development.
Is Crohn's disease genetic or environmental?The causes of Crohn disease are complex. This condition results from a combination of genetic, environmental, and lifestyle factors, many of which are unknown. Many of the major genes related to Crohn disease, including NOD2, ATG16L1, IL23R, and IRGM, are involved in immune system function.
What are environmental triggers for IBD?Air pollution, a consequence of the progressive contamination of the environment by countless compounds, is another factor associated with IBD, as particulate matter or other components can alter the host's mucosal defences and trigger immune responses.
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