Together with an international research team, CoE Key Researcher Martin Polz, CoE Key Researcher Shaul Pollak (CeMESS, University of Vienna), and first author Xiaoqian Annie Yu show that many gut bacterial species are not uniform, but consist of multiple evolutionarily distinct populations that have adapted to different conditions in the human gut.
Using a reverse ecology approach based on large-scale genomic and metagenomic data, the researchers identified signals of strong natural selection and found that some of these bacterial populations are associated with ageing, inflammatory bowel disease, colorectal cancer, and type 2 diabetes.
They also demonstrate that highly successful bacterial lineages can spread globally within just a few decades, indicating that microbiome composition is influenced not only by diet and medication, but also by transmission between people.
These findings could improve how microbiome biomarkers are identified and may eventually enable more precise, targeted microbiome-based therapies.