How Western Diets Are Altering Gut Microbiomes in Immigrant Populations

Recent research conducted by scientists at the University of British Columbia highlights significant changes in the gut microbiomes of Indo-Canadians as they adopt more Westernized dietary habits. The study, involving over 170 participants from India and Canada, observed that immigrants and first-generation Indian migrants experience a marked shift in their gut bacteria and dietary patterns, especially when living in Western environments.

Indians in their native country predominantly harbor gut bacteria like Prevotella, which are associated with high-fiber, plant-based diets. However, Indo-Canadians and recent immigrants show a decline in these beneficial bacteria and an increase in microbes typical of Westernized diets, such as Blautia and Anaerostipes. Their diets tend to be richer in ultra-processed foods, with Indo-Canadians deriving over 60% of their daily calories from these foods, contrasted with just 12% among Indians. Correspondingly, fiber intake drops significantly among immigrants.

These microbial shifts are not merely biological curiosities; they are linked to increased health risks, particularly inflammatory bowel disease (IBD). The incidence of IBD among South Asians in Canada is more than six times higher than in India, suggesting that dietary acculturation—moving away from traditional, fiber-rich diets toward processed, high-sugar foods—plays a major role.

Professor Deanna Gibson emphasizes that the gut microbiome is highly adaptable and responds directly to dietary changes. As migrants navigate between traditional and Western diets, their microbiomes become transitional, potentially increasing susceptibility to chronic diseases.

The study underscores the global implications of dietary Westernization, especially as international migration and food industrialization accelerate. Such changes influence gut health and disease risk worldwide, calling for culturally sensitive dietary guidelines and health strategies tailored for immigrant communities.

Given the rapid rise of IBD and other chronic conditions, understanding how diet influences the microbiome could be vital in developing preventive measures. Encouraging the preservation of traditional dietary habits might serve as a protective factor against these health issues.

Source: https://medicalxpress.com/news/2025-09-spice-sugar-westernized-diets-reshaping.html