Stanford scientists map the molecular diversity of different global populations

Researchers at the Stanford School of Medicine have found that ethnicity and geography may influence human molecular makeup - from metabolism and immunity to gut microbiota and biological aging.

The findings, which will be published in Cell on May 14th, 2026, illuminate the complex interplay between genetics and the environment, providing insights for researchers and clinicians seeking to better understand health care for diverse populations.

The preliminary findings offer new leads for additional exploration into how one's ethnicity and environment affect many aspects of their biology. Michael Snyder, PhD, the Stanford W. Ascherman, MD, FACS Professor in Genetics, is a co-senior author of the study. Nasim Barapour, PhD, a research scientist, is a co-lead author.

The study employed a sweeping analytical approach, measuring a variety of molecules in the human body - including lipids, microbes, proteins, and metabolites (molecules that represent one's metabolic activity) - to construct a new view of human molecular diversity across populations and geographies.

For the first time, we have deeply profiled people from around the world," Snyder said. "This enables us to see what properties, such as metabolites and microbes, are correlated with ethnicity and which ones with geography."

Michael Snyder, PhD, Stanford W. Ascherman, MD, FACS Professor, Genetics, Stanford Medicine

A global molecular portrait

The researchers analyzed samples from 322 healthy individuals - all attending a conference together - of European, East Asian, and South Asian ancestry living in Asia, Europe, and North America. Having participants of the same ethnic background but different geographic locations allowed the researchers to disentangle the effects of genetic ancestry from those of environment.

The study identified some ethnicity-associated molecular signatures: South Asian participants showed higher levels of pathogen exposure, for example, while individuals of European ancestry displayed greater gut microbial diversity and elevated levels of metabolites associated with cardiovascular disease. These patterns held regardless of where participants lived, pointing to a strong genetic component in shaping human molecular identity.

Where people live also leaves a measurable imprint on biology. Geographic relocation, meaning those who no longer live on the continent of their ancestors, was associated with significant shifts in metabolic and lipid networks - including cholesterol, bile acid, and arachidonic acid pathways - as well as selective changes in the gut microbiome.

One of the study's most striking discoveries, Snyder said, concerns the relationship between geography and biological age - a measure of how old the body's cells and tissues appear at the molecular level, which can differ from chronological age.

"East Asians who live outside of Asia have a higher biological age than those residing in Asia. For Europeans, those residing outside of Europe are younger," Snyder noted.

These divergent aging patterns underscore how the environment may modulate biological age, and they raise important questions about lifestyle, diet, and microbiome factors that may accelerate or slow the aging process.

Novel molecular connections

Among the study's novel mechanistic findings, researchers identified a link between the expression of a key telomerase gene - associated with cellular aging and longevity - and the gut microbe Oscillospiraceae UCG-002, mediated by sphingomyelin, a lipid molecule. This finding opens avenues for understanding how the gut microbiome may influence aging at the molecular level.

The dataset generated by this study is an open-access resource that will be valuable for advancing precision medicine - tailoring medical treatment to the individual characteristics of each patient, Snyder said. By elucidating how ethnicity and environment interact to shape molecular biology, the findings lay the groundwork for more equitable and effective diagnostics, therapeutics, and preventive strategies for diverse global populations.