Is a move to a new city, or even a new country, literally changing you from the inside out? New research suggests the answer is a resounding yes – and not always for the better. A groundbreaking study reveals that when people migrate, the trillions of tiny microbes living in their gut, known as the gut microbiome, undergo a dramatic transformation. This isn’t just a minor shift; it appears to significantly increase the risk of developing serious conditions like heart disease and diabetes.
Imagine your gut as a bustling, microscopic city. Different types of bacteria, fungi, and other microorganisms live there, each playing a role in your health. This new research, published in the journal Gut Microbes, found that when people move, especially from traditional rural settings to modern urban environments or even across continents, the population of this “gut city” changes. In many cases, beneficial microbes that were once abundant disappear, while others, potentially less helpful ones, emerge. The researchers observed 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.” This provides a compelling link between where you live, what’s inside you, and your long-term health.
The Microbial Migration: How the Study Unfolded
To understand this fascinating connection, researchers embarked on an ambitious project, studying more than 1,100 Ghanaian individuals. This diverse group was carefully chosen from three distinct locations: rural Ghana, urban Ghana, and Amsterdam, in the Netherlands. This unique setup allowed scientists to track changes in the gut microbiome as people moved from a more traditional rural lifestyle to increasingly urbanized areas, and eventually to a different continent.
Between 2019 and 2021, all participants underwent a standardized set of health checks. This included answering detailed questions about their general health and diet (using specific tools like the semi-quantitative Food Propensity Questionnaire and 24-hour dietary recalls in a subsample), getting physical exams, providing blood samples, and, crucially, collecting stool samples for gut microbe analysis. The blood tests measured key indicators of heart health and diabetes risk, such as blood sugar (glucose and HbA1c) and cholesterol levels. Body weight, height, and blood pressure were also recorded.
To analyze the gut microbes, scientists extracted DNA from the stool samples. They then used advanced genetic sequencing to identify and count the different types of bacteria present in each person’s gut by amplifying the 16S rRNA gene. Handling this massive amount of data required sophisticated computer models, specifically XGBoost models, which helped them pinpoint exactly which microbes were different between the groups and how these differences related to the participants’ health.
What the Researchers Discovered
The findings were striking: the gut microbiome shifted considerably as people moved from rural Ghana to urban Ghana, and then to Amsterdam. For example, a type of beneficial bacteria called Prevotellaceae was much more common in rural Ghanaians but decreased significantly as people moved to cities and then to Amsterdam. On the flip side, other bacterial families, like Lachnospiraceae and Bacteroidaceae, became more common in the guts of Ghanaians living in Amsterdam. A particularly notable finding was the near disappearance of Weisella species, a kind of bacteria commonly found in Ghanaians back home, but almost absent in those living in Amsterdam.
The variety of microbes also changed. Individuals in rural Ghana had the most diverse gut microbiomes, meaning a wider range of different microbial species. This diversity generally decreased as people migrated, with Amsterdam Ghanaians having the least diverse microbiomes. This pattern was observed in both “alpha diversity” (the variety within an individual’s gut) and “beta diversity” (the differences between groups).
The researchers also looked into what might be causing these changes. Diet emerged as a significant factor. For example, a higher intake of protein, salt, and fat was strongly linked to differences in gut bacteria. These dietary components were found to be higher in migrants. Body weight also played a crucial role; Amsterdam Ghanaians had a significantly higher average body mass index (BMI) compared to rural Ghanaians (almost 6 kg/m² higher), which also influenced the gut microbiome. The study also observed that rates of high blood pressure and diabetes were lowest in the rural population and highest in Amsterdam Ghanaians.
Health Implications: More Than Just a Belly Ache
The alterations in gut microbes carry significant health implications. The study directly connected the changes in gut bacteria along the migration path with an increased risk for serious health issues like heart disease and diabetes. This indicates that as people’s gut microbiomes adapt to new environments, so does their susceptibility to chronic diseases that are common in Western societies.
This research highlights a crucial point: “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,” explained Charles Agyemang, Professor of Global Migration, Ethnicity & Health at Amsterdam UMC and a senior author of the study. This provides a vital piece of the puzzle in understanding why migrant populations sometimes face different health challenges compared to the native residents of their new home. While diet is a major player, the gut microbiome is a complex system influenced by many factors, including lifestyle and stress. The study offers strong evidence that migration significantly impacts this internal ecosystem, with clear consequences for human health.
Shaping Health for a Mobile World
This study underscores a powerful reality: our environment profoundly influences our internal health. The connection between migration, gut health, and the risk of chronic diseases is now clearer than ever. These findings call for continued research and proactive measures to support the health of individuals navigating new environments. Understanding how to maintain a healthy gut microbiome during migration could be a key strategy in improving the well-being of people worldwide as our societies become increasingly interconnected.
Paper Summary
Methodology
The study collected follow-up data from 1,177 Ghanaian participants across rural Ghana, urban Ghana, and Amsterdam, Netherlands, between 2019 and 2021. Researchers gathered health questionnaires, dietary information, physical measurements, blood samples for cardiometabolic markers, and stool samples for gut microbiota analysis using 16S rRNA gene sequencing. Data was analyzed with statistical methods including machine learning (XGBoost models) to identify microbial shifts and their associations with health outcomes.
Results
A significant shift in gut microbiota composition was observed along the migration axis. Prevotellaceae decreased, while Lachnospiraceae and Bacteroidaceae increased in migrants, with Weisella species almost disappearing in Amsterdam Ghanaians. Gut microbial diversity was highest in rural Ghanaians and lowest in Amsterdam. Migrants had higher intakes of protein, salt, and fat, which were linked to gut microbial differences. Amsterdam Ghanaians also showed higher BMI, hypertension, and diabetes rates compared to rural Ghanaians, and specific microbial changes were associated with these adverse cardiometabolic outcomes.
Limitations
The study identifies associations, not causation, and notes that dietary intake only partly explains the observed microbial shifts. Taxonomic assignment for some microbes was limited to family or genus level. The study did not include smoking or alcohol use in all analyses due to low prevalence. Future longitudinal studies are needed to confirm findings and establish causality.
Funding and Disclosures
The study was led by Amsterdam UMC in collaboration with the University of Ghana and Kwame Nkrumah University of Science & Technology (KNUST). It was published as an Open Access article under the Creative Commons Attribution License. The genetic sequencing data and analytical code are publicly available.
Publication Information
Article Title: Gut microbiota shift in Ghanaian individuals along the migration axis: the RODAM-Pros cohort Authors: Barbara J. H. Verhaar, Eva L. van der Linden, Charles F. Hayfron-Benjamin, Ellis Owusu-Dabo, Samuel N. Darko, Sampson Twumasi-Ankrah, Peter Henneman, Erik Beune, Karlijn A.C. Meeks, Max Nieuwdorp, Hilde Herrema, Bert-Jan H. van den Born & Charles Agyemang Journal: Gut Microbes Volume: 17 Issue: 1 Article ID: 2471960 DOI: 10.1080/19490976.2025.2471960 Published Online: 06 April 2025 Publisher: Taylor & Francis Group, LLC