Mapping Early Migration of Stomach Ulcer Bacteria

If you're suffering from a stomach ulcer, you can take comfort in the fact that humans have suffered for thousands of years from the affliction...:)

An international team of scientists has discovered that the ubiquitous bacteria that cause most painful stomach ulcers have been present in the human digestive system since modern man migrated from Africa over 60,000 years ago. The research, published online today (7 February) by the journal Nature, not only furthers our understanding of a disease causing bacteria but also offers a new way to study the migration and diversification of early humans.

The international research collaboration was led by scientists from the University of Cambridge, the Max Planck Institute in Berlin, and the Hanover Medical School. The researchers compared DNA sequence patterns of humans and the Helicobacter pylori bacteria now known to cause most stomach ulcers. They found that the genetic differences between human populations that arose as they dispersed from Eastern Africa over thousands of years are mirrored in H. pylori.

Human DNA analysis has shown that along the major land routes out of Africa human populations become genetically isolated – the further from Eastern Africa a population is the more different genetically it is compared to other human populations. Other research has shown gradual differences in European populations, presumed to be the result of Neolithic farmers moving northwards. The international H. pylori research team found almost exactly the same genetic distribution patterns in their results.

The scientists combined their genetic analysis with a computer simulation that modelled the spread of the bacteria across the globe. This showed that it migrated from Eastern Africa at almost exactly the same time as early humans, approximately 60,000 years ago.



Source: BBSRC