Dietary changes post-migration alter gut microbiome to increase heart disease risk, study finds

An Amsterdam UMC-led study has found that migrants, in this case from West Africa to Europe, experience a “clear change” in their microbiome composition compared to their non-migrant peers in West Africa, which exposes them to an increase in cardiovascular disease.

These peer-reviewed findings are published in the journal Gut Microbes, demonstrating that participants who lost specific groups of microbes or acquired specific new groups of microbes had higher rates of cardiovascular risk factors such as hypertension, diabetes, obesity, and poor kidney function.

“The results clearly demonstrate the importance of our findings in relation to migration-related health outcomes,” explains postdoctoral researcher at Amsterdam UMC and first author of the study, Barbara Verhaar, who carried out the research together with colleagues at the University of Ghana, and Kwame Nkrumah University of Science & Technology (KNUST).

“It was already thought that migration had an effect on an individual’s microbiome, but previous studies have either lacked in the number of individuals included, didn’t control for variations in diet or only compared first- and second-generation migrants. Our study makes use of our own RODAM study cohort to definitively demonstrate this change,” says Verhaar.

The Amsterdam UMC-led study included more than 1,100 individuals from two separate continents and three locations: rural Ghana, urban Ghana and the Netherlands. Respondents completed identical dietary questionnaires and provided both fecal and blood samples to determine the composition of their gut microbiomes.

Analyses revealed the presence of different microbes across the three groups, in line with the hypothesis that migration would affect microbiome composition. The findings show that some groups of microbes disappear, and new ones emerge along the migration axis.

Previous studies, as well as the World Health Organization, note that migrants frequently experience poorer health outcomes than native residents, and research from Amsterdam UMC has found this also to be the case in the Netherlands.

“This research underscores the relevance of gut health and how we look at the adverse health outcomes that are often associated with migration,” adds Charles Agyemang, Professor of Global Migration, Ethnicity & Health at Amsterdam UMC and senior author of the study.

“It is fascinating to learn that when we migrate, we lose some relevant microbes we acquired in our home countries and pick up new microbes in the new countries, and this can influence our health very importantly.

“We found that macronutrient groups such as protein, fat and salt in food were strongest associated with gut microbiota composition and these were higher in migrants, which might have contributed to the shift in gut microbiota composition. Future longitudinal studies are needed to verify these findings.”

Cardiometabolic risk is a growing concern for researchers across the globe and Agyemang is currently leading a host of projects, both in the Netherlands and several African countries, that aim to develop better interventions to lower the risk of developing cardiometabolic diseases, such as diabetes and hypertension; and to improve management of cardiometabolic diseases.

As part of these efforts, as in this study, he works with several institutions across the globe, especially in the African region, to ensure that research in Amsterdam is strengthened with international data and, also, that research findings are translated into concrete policy.

“The findings of this study provide important insights into how migration can reshape our gut microbiota and subsequent health outcomes and emphasize the need for north-south collaborations,” adds Ellis Owusu-Dabo, Professor of Epidemiology and Global Health, KNUST.