Abstract P208: Dietary Acculturation Impacts the Gut Microbiome in a Diverse U.S. Population

Abstract

Introduction: Risk of chronic diseases such as obesity, diabetes, and cardiovascular disease are known to increase with duration and generations of U.S. residence, though it remains unclear how living in the U.S. negatively impacts immigrant health. Hypothesis: We hypothesize that dietary acculturation, or shifting of dietary patterns towards a native U.S. pattern, contributes to the disease risk transition in immigrants, via modulation of the gut microbiome. Methods: We characterized disparities in the gut microbiome between racially/ethnically diverse U.S. immigrant and U.S.-born groups, and determined the impact of dietary acculturation on the microbiome. Stool samples were collected from 863 U.S. residents, including U.S.-born (315 White, 93 Black, 40 Hispanic) and foreign-born (105 Hispanic, 264 Korean) groups. We determined dietary acculturation from dissimilarities based on food frequency questionnaires ( Figure 1a ), and used 16S rRNA gene sequencing to characterize the microbiome. Results: Gut microbiome composition differed across study groups, with the largest difference between foreign-born Koreans and U.S.-born Whites ( Figure 1b ). Bacteroides plebeius , a seaweed-degrading bacterium, was strongly enriched in foreign-born Koreans, while Prevotella copri and Bifidobacterium adolescentis were strongly enriched in foreign-born Koreans and Hispanics, compared with U.S.-born Whites. Dietary acculturation in foreign-born participants was associated with specific sub-operational taxonomic units (s-OTUs), resembling abundance in U.S.-born Whites ( Figure 1c-d ); e.g., a Bacteroides plebeius s-OTU was depleted in highly diet-acculturated Koreans. Conclusions: Dietary acculturation may result in loss of native species in immigrants. Longitudinal research is necessary to determine the role that acculturation-related microbiome changes may play in immigrant and racial/ethnic health disparities.