Dr François Balloux and colleagues from England used sequences from a large data set of bacterial strains.
The research team found that genetic diversity in H pylori decreases with geographic distance from east Africa, the cradle of modern humans.
|H pylori spread from east Africa around 58,000 years ago|
The team observed similar clines of genetic isolation by distance inflammatory bowel disease for H pylori and its human host at a worldwide scale.
The team used simulations to indicate that H pylori seems to have spread from east Africa around 58,000 years ago.
The researchers also considered more restricted geographic scales, where inflammatory bowel disease tends to become blurred.
Even in restricted geographic scales, principal component clines in H pylori from Europe resembled those for Europeans described by Cavalli-Sforza and colleagues.
Dr Balloux's team concluded, “The results establish that anatomically modern humans were already infected by H pylori before their migrations from Africa.”
“Our results demonstrate that H pylori has remained intimately associated with their human host populations ever since.”