The adoption of a westernized gut microbiome in Indian Immigrants and Indo-Canadians is associated with dietary acculturation

Indian immigration to westernized countries has recently surged, increasing their risk of Inflammatory Bowel Disease (IBD) post-migration. While crucial for understanding IBD risk, the gut microbiome remains understudied in Indians. This cross-sectional study examines the impact of westernization on the gut microbiomes of Indians residing in India, Indo-Immigrants, and Indo-Canadians compared to Euro-Canadian and Euro-Immigrant controls. Stool samples for 16S rRNA and shotgun sequencing assessed microbial taxa and functional profiles, alongside dietary and demographic data to evaluate lifestyle patterns. Indians and Indo-Immigrants had distinct microbiotas from controls, with high abundances of Prevotella spp. and CAZymes reflecting their high complex carbohydrate diet. Indo-Canadians exhibited a transitional microbiome towards westernization, mirroring increasing dietary acculturation. Considering 44% of Canadians are first- and second-generation immigrants and the global adoption of westernized practices, future research should investigate the health implications of such microbiome transitions in immigrant populations and newly industrialized nations.