The researchers say this suggests environment and genetic ancestry interact in surprising ways that could speed up or slow down ageing.
The study also uncovered a never-before-seen link between a telomerase gene involved in cellular ageing and a specific gut microbe, connected through a lipid molecule called sphingomyelin.
This unexpected three-way link hints at a molecular chain reaction through which gut bacteria may influence how quickly our cells age.
The findings create a powerful new resource for precision medicine, highlighting the need for healthcare tailored to genetic ancestry and environment rather than a one-size-fits-all model.
The researchers say their open-access dataset will help scientists and clinicians develop more accurate diagnostics, treatments and prevention strategies tailored to genetic ancestry, environment and individual biology.
“What this study shows, more clearly than ever before, is that our biology is shaped by a combination of both our genetic ancestry and the places we live,” said co‑author Professor Richard Unwin from The University of Manchester.
Manchester carried out analysis of biological metals alongside the international groups looking at proteins, the immune system, metabolism and microbiomes to generate a massive integrated picture of human variability.
Professor Unwin added: “We were struck by how consistently ethnicity influenced immunity, metabolism and the microbiome, even when people moved thousands of miles away.
“However, it is equally clear that where we live can have substantial impacts on nudging key molecular pathways — even how our cells appear to age — in different directions depending on who you are. It proves that precision medicine must reflect real global diversity, not a single population.”
Michael Snyder, Professor of Genetics at the Stanford School of Medicine who led the study said: “Our study is special because for the first time we have deeply profiled people from around the world, including Asia, Europe and North America. This enables us to see what properties such as metabolites and microbes are associated with ethnicity and which ones with geography.
“One interesting finding is the association of age with geography. East Asians that live outside of Asia have a higher biological age than those residing in Asia. For Europeans, those residing outside of Europe are younger.”
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