Helicobacter pylori could have caused stomach ulcers in ancient Mexico

Yolanda Lòpez-Vidal and colleagues from the National Autonomous University of Mexico studied the stomach, tongue-soft palate and brains of two naturally mummified corpses - one young boy and one adult male. The researchers looked for the presence of fragments of H. pylori DNA in the remains after amplification by polymerase chain reaction.

According to Lòpez-Vidal: “Our results show that H. pylori infections occurred around 1350AD in the area we now know as Mexico.” Although previous research has suggested that H. pylori was present in these communities, this is the first evidence that it caused gastric infections.

Lòpez-Vidal said: “It is only through the use of the stomach tissue of these incredible mummies that we were able to make this discovery. Infection is established when the micro-organism infiltrates the stomach lining and induces a local inflammatory response. This is unlike colonisation, which does not cause such a response and does not occur in the stomach”.

Mummification, or the preservation of a body in the process of putrefaction, can take place as a result of environmental effects or as a result of human intervention - as in the case of the mummies found in Egyptian pyramids. In Mexico, mummies are found in dry places such as caves and rock shelters, where rapid dehydration occurs. Luckily for the purposes of this study, the internal organs are the last to dehydrate.

As well as stomach ulcers, H. pylori causes gastritis, duodenitis, and cancer. It is a helix-shaped bacteria that is believed to be transmitted by the ingestion of food or water contaminated with faecal matter.