This idea changes how we think about heredity. Genes may shape behavior, immune signals, or the chemicals organisms produce, and those changes create environments that favor certain microbes. When microbes move between individuals who share space, those genetically influenced microbes amplify their effects across a group. Accounting for this social flow of microbes revealed a much larger role for host genetics in shaping the microbiome than earlier studies reported.
For people, the findings raise questions about health, learning, and inclusion. If our genetic traits help shape others’ microbiomes through shared environments, then housing, caregiving, and social networks could influence biological outcomes in unexpected ways. Follow the full study to see how these microbial connections might extend our ideas about growth, resilience, and who benefits when environments are made healthier for everyone.
Scientists studying thousands of rats discovered that gut bacteria are shaped by both personal genetics and the genetics of social partners. Some genes promote certain microbes that can spread between individuals living together. When researchers accounted for this social sharing, genetic influence on the microbiome turned out to be much stronger than previously thought. The study suggests genes can affect others indirectly, without DNA ever being exchanged.
