Inflammatory Bowel Disease in Asia: The Challenges and Opportunities

found that a Western style diet, hygiene, and childhood immunological factors are associated with IBD in Asia, all of which are the results of urbanization. 8,9 Studies in Asia have started to link environmental factors with changes of the gastrointestinal microbiota. 9,10 The fundamental aspects of the pathogenesis of IBD are correlated with the abnormal mucosal immune response to antigenic stimulation from the gut microbiota secondary to environmental influence, with the background of genetic susceptibility. It has been suggested that the low incidence of IBD in the Asian population may be due to less IBD-susceptible genes compared to that in Westerners. The IBD-susceptible genes that have been firmly associated with CD in the Caucasian population such as NOD2 , interleukin (IL)-23R , and ATG16L1 showed no correlation with CD in Japanese, Korean, and Chinese Han patients with CD, except IL-23R had a weak association with Korean CD patients. 11 However, single nucleotide polymor-phisms (rs3810936, rs6478108, and rs7848647) on TNFSF15 have been identified to be more strongly associated with Asian CD patients than with Caucasian CD patients. 11 To date, few epidemiological studies have been performed in Asia, because there is a lack of national registries in most Asian countries. Only a few novel Asian IBD-associated genes have been identified, and the study of epigenetic alteration just recently emerged in Asia. Studies on the interaction of environmental factors, gut microbiota, and susceptible genes in Asia should be focused on in the future. Since all these challenges exist, collaborative works should also be performed. Longitudinal studies on the early occurrence of IBD in Asia and cross-sectional studies among countries or the different ethnicities in Asia will provide amazing opportunities for Asian researchers. The incidence and prevalence of IBD, including UC and CD, has been increasing rapidly in Asia over the last two decades. 1 Dilemmas are arising along with an increasing number of patients with IBD in Asia. For example, the knowledge on IBD has not been popularized in the vast area of Asia, and many IBD patients still do not receive a timely diagnosis and appropriate treatment. In addition, health care for patients with IBD has not received sufficient attention. How can these challenges be turned into opportunities? Alternatively, these challenges can be used to encourage Asian doctors and investigators to obtain more diagnostic and therapeutic skills for managing IBD. Asian researchers can use the growing IBD incidence to explore the …