Environmental Changes and the Onset of Inflammatory Bowel Disease (IBD) in the Migrant South Asian Population

Abstract

Purpose: The increase in the incidence of IBD in South Asian patients over the past 2 decades has been attributed to both genetic and environmental factors. A comprehensive evaluation of hygiene and dietary changes among the Indian diaspora to the U.S. has never been conducted. Methods: In this pilot study, we administered a questionnaire to first generation Indian immigrants with IBD in Northern California. The questions were extensive and involved changes in diet, stress, hygiene and lifestyle after immigration from India to the U.S.A. Results: Twenty patients are enrolled to date. 12 ulcerative colitis (UC) patients and 8 Crohn's disease (CD) patients were surveyed. Average number of years since migrating to the United States was 22.5 years (11-50 years). Average number of years from time of migration to time of diagnosis was 11.9 years (3-40 years) Average age at diagnosis was 35 years (17-68 years). Significant dietary changes were noted upon immigration. These include increase in animal protein and fat intake, the consumption of pasteurized milk, adoption of a more western diet instead of traditional Indian diet, decreased consumption of freshly prepared foods, consistent daily use of the microwave and the consumption of pre-prepared or packaged foods (Table 1). 25% of UC and 12.5% of CD patients had ever smoked. 50% UC and 62.5% of the CD patients consumed any alcohol. Environmental changes include access to running hot water, switch to the use of toilet paper instead of water, appropriate hand washing techniques and use of hand sanitizer (Table 2). Life style changes included increased perceived stress which was seen in 83.3% UC and 87.5% CD patients. 95% of all patients surveyed came from a lower socioeconomic status prior to migrating to the U.S. with annual household incomes below $20,000. However, upon migration 85% had average annual household incomes above $80,000. 58.3% UC and 75 % of CD patients had no refrigerator while growing up in India. Improved oral hygiene was observed in 50% of UC and 87.5% CD patients. 41.6 %UC patients and 50% CD patients had a family history of IBD. However, in all affected family members, the symptoms and diagnosis of IBD occurred only after migration to the U.S. Conclusion: South Asian immigrants with IBD note a significant change in diet, hygiene and lifestyle after arrival in the US. Further studies will be done to compare these patients to non-IBD migrant controls and to determine microbiome variations with immigration and disease onset.