Why IBD rates are rising in South Asians

Authored By: Anwesa Brahmachary

Art By: Alex Peng

With changing diet patterns, the rates of obesity, inflammatory bowel disease (IBD), and other related diseases are also rapidly changing. However, there is a disparity in how various communities are impacted by these changes [1]. According to a study done in the Inflammatory Bowel Diseases, between 2000 and 2013, South Asian IBD diagnosis has increased by 97% in the United States, which demonstrates potential correlations between changed environmental exposures and IBD rates for migrant populations [2]. Further, studies have shown that the gut microbiota composition of South Asians, specifically Bangladeshis, differs from that of other ethnicities [3]. Symptoms of Inflammatory Bowel Disease can manifest differently in South Asians and the treatment choices South Asians make after diagnosis may also contribute to the way IBD manifests in South Asians. The impact of culture on these choices is also an important factor to consider [4]. In order to address disparities between IBD in South Asians and other populations, it is important to make decisions regarding treatment with the causes of these disparities in mind.

To begin, the composition of the gut microbiota plays a role in the development and severity of IBD. More specifically, the ratio of different types of good and bad bacteria in the microbiome, as well as dysbiosis, has been shown to have varying levels based on the type of metabolic disease, with examples being Crohn’s disease and Ulcerative Colitis [5]. When it comes to disparities in IBD, it is therefore important to evaluate gut microbiome composition differences. A study was done on the gut microbiome composition of different ethnicities of Bangladeshi individuals with varying diets. Results showed that compared to individuals from other countries, Bangladeshi individuals have a more varied gut microbiota composition [3]. This finding is significant as it shows that Bangladeshis specifically can have varied mechanisms, severity, and more when it comes to Diabetes, IBD, and other metabolic diseases. Furthermore, variations were shown even within the population, with Bengali populations having varying gut microbiota ocmposition compared to Bangladeshi indigenous populations, as a result of diet variations, thus showing the severity of the impact diet can have on the gut microbiota status of individuals [3]. This further indicates a need for ethnicity-specific studies on IBD to develop the most effective interventions.

Additionally, in South Asian immigrant populations, when individuals move from a region with low IBD rates to one with high IBD rates, they face a higher risk of developing IBD. It was shown that second-generation South Asian immigrants had higher IBD rates [2], which is likely due to the increased consumption of processed foods and corresponding decrease in fiber, PUFA, and other important positive food components [6]. This was investigated in South Asian Canadian immigrants. In a study by Copeland et al., results showed that first-generation South Asian Canadian immigrants had more P.copri, while the second generation had more Bacteroides. This shift in gut bacteria composition is seen alongside a shift in rates of diseases such as Diabetes and IBD from first-generation to second-generation [5]. This indicates that there might be a relationship between gut composition and disease development within immigrant populations. As a result, the treatment of immigrant populations incorporating changing environments and diets is crucial in IBD treatment.

Furthermore, when it comes to IBD, variations are also seen for South Asians in terms of symptoms, handling of diagnosis, and treatment. South Asians with Inflammatory Bowel Disease have been seen to have higher rates of rectal pain, perianal disease, and more; however, they were also less likely to be placed on more than one biologic [2]. This displays a lack of treatment such as management catered to severity of symptoms, which varies amongst different races. Cultural differences may also play a role in disease prevalence. An analysis done in a study showed that South Asian patients had a linguistic barrier in understanding what IBD was after diagnosis, which impacted whether individuals chose to take action regarding their diagnosis. Differences in religion and culture likely also play a part in their diets even after being diagnosed with IBD. The study also discusses stigma around IBD diagnosis, choosing alternate diets containing fewer spice levels, and other barriers in the South Asian community when it comes to IBD [1]. Conversations need to be created around these differences in order to cater treatment to South Asian individuals in the most effective manner for them.

With statistics showing South Asians having an increasing rate of IBD in recent years, it has become increasingly important to discuss IBD development with an intersectional perspective that is inclusive of South Asians. Especially in terms of culture, conversations need to be created in order to remove the stigma around and increase awareness regarding IBD; this can lead to differing choices being made in terms of diet and lifestyle more comfortably. Furthermore, in the healthcare field itself, awareness of the differences in gut microbiota composition, IBD rates and symptoms of immigrants based on time in the country(Canada, United States, etc) can help bridge disparities when it comes to treatment for South Asians. It is important to deliver culturally competent care in order to achieve the best results and bridge disparities.

Works Cited:

1. Mukherjee, S., Beresford, B., Atkin, K., & Sebastian, S. (2020, June 23). The need for culturally competent care within gastroenterology services: Evidence from research with adults of South Asian origin living with inflammatory bowel disease. OUP Academic. https://academic.oup.com/ecco-jcc/article/15/1/14/5861668 

2. Jangi, S., Ruan, A., Korzenik, J., & de Silva, P. (2020, March 2). South Asian patients with inflammatory bowel disease in the United States demonstrate more fistulizing and perianal crohn phenotype. OUP Academic. https://academic.oup.com/ibdjournal/article/26/12/1933/5771121?login=true 

3. Ahammad, I., Bhattacharjee, A., Chowdhury, Z. M., Rahman, A., Hossain, M. U., Dewan, G., Talukder, S., Das, K. C., Keya, C. A., & Salimullah, M. (2024, April 25). Gut microbiome composition reveals the distinctiveness between the Bengali people and the indigenous ethnicities in Bangladesh. Nature News. https://www.nature.com/articles/s42003-024-06191-9#:~:text=Bengali%20population%20possessed%20lower%20Firmicutes,microbiome%20of%20all%20Bangladeshi%20populations. 

4. Qiu, P., Ishimoto, T., Fu, L., Zhang, J., Zhang, Z., & Liu, Y. (2022, January 24). The gut microbiota in inflammatory bowel disease. Frontiers. https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.733992/full#B105 

5. Copeland, J. K., Chao, G., Vanderhout, S., Acton, E., Wang, P. W., … Benchimol, E. I. (2021). The Impact of Migration on the Gut Metagenome of South Asian Canadians. Gut Microbes, 13(1). https://doi.org/10.1080/19490976.2021.1902705

6. Foster, A., & Jacobson, K. (2013, October 21). Changing incidence of inflammatory bowel disease: Environmental influences and lessons learnt from the South Asian population. Frontiers. https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2013.00034/full