The role genetics and gut bacteria play in human health has long been a fruitful source of scientific enquiry, but new research marks a significant step forward in unraveling this complex relationship. Its findings could transform our understanding and treatment of all manner of common diseases, including obesity, irritable bowel syndrome, and Alzheimer’s disease.

The international study, led by the University of Bristol and published today in Nature Microbiology, found specific changes in DNA — the chains of molecules comprising our genetic make-up — affected both the existence and amount of particular bacteria in the gut.

Lead author Dr David Hughes, Senior Research Associate in Applied Genetic Epidemiology, said: “Our findings represent a significant breakthrough in understanding how genetic variation affects gut bacteria. Moreover, it marks major progress in our ability to know whether changes in our gut bacteria actually cause, or are a consequence of, human disease.”