As reported in the January 2024 issue of the American Journal of Biological Anthropology, Fanfan and associates adapted the National Institute on Minority Health and Health Disparities' research framework to propose a conceptual model that considers the intersection of SDoH, the microbiome, and health outcomes in immigrants. This conceptual approach was used as a lens through which to explore recent research about SDoH, biological factors associated with changes to immigrants' microbiomes, and long-term health outcomes. Seventeen articles were reviewed, indicating that dietary acculturation; physical activity; ethnicity; birthplace; age at migration and length of time in the host country; socioeconomic status; and social/linguistic acculturation were important determinants of postmigration microbiome-related transformations. These factors are associated with progressive shifts in microbiome profile with time in host country, increasing the risks for cardiometabolic, mental, immune, and inflammatory disorders and antibiotic resistance. The evidence thus supports the premise that SDoH influence immigrants' health postmigration, at least in part, through their effects on the microbiome.
Omission of important postmigration social-ecological variables (e.g., stress, racism, social/family relationships, and environment), limited research among minoritized subgroups of immigrants, complexity and inter- and intra-individual differences in the microbiome, and limited interdisciplinary and biosocial collaboration restrict an understanding of this area of study. To identify potential microbiome-based interventions and promote immigrants' well-being, more research is necessary to understand the intersections of immigrant health with factors from the biological, behavioral/psychosocial, physical/built environment, and sociocultural environment domains at all social-ecological levels. The authors point out that international migrants number more than 272 million individuals out of a global population of more than 7.7 billion. Global conflict, environmental disasters, economic necessity, and the desire for a better life will continue to drive high levels of migration worldwide. Although immigrants from less-developed to more-developed countries tend to have better health in birth outcomes, cardiometabolic health, and mental health relative to native-born populations upon migration, compelling evidence demonstrates that this health advantage erodes with increased time in the host country.