A team of international scientists has identified and fully sequenced the genome of Heliobacter pylori from the stomach of the 5300 year old Copper Age “iceman” mummy named Ötzi that was discovered in 1991 in a glacier in the Ötztal Alps on the border of Italy and Austria, according to a study published in Science.

Because H pylori is present in half the world’s current population, this information may lead to a better understanding of the evolution, transmission and treatment of pathogens, Albert Zink, PhD, head of the Institute for Mummies and the Ice Man, explained in an interview with Infectious Disease Advisor.

Dr Zink, Frank Maixner, PhD, microbiologist, both of the European Academy of Bozen/Bolzano (EURAC) and a team of international scientists performed a biopsy and examined 12 samples from Ötzi, including the contents of his stomach, small and large intestines as well as mucosa tissue.1 They used polymerase chain reaction, metagenomics analysis and targeted genome capture.


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“Metagenomic analysis yielded endogenous ancient H pylori DNA (15,350 reads) in all gastrointestinal tract contents,” Dr Zink and colleagues reported. They noted that it was not possible to tell if Ötzi suffered H pylori related disease as there was no stomach tissue to study. Only 10% of people with H pylori today experience stomach ulcers or cancer, according to the study.

Researchers used the strain to track human migration. The samples were typed as being “a nearly pure representative” of the H pylori that originated in Asia, and is still found in populations living in the central and southern areas of that continent. This was a surprise for researchers, and they said this indicated that the admixture of the Asian strain with a H. pylori strain that originated in Northern Africa and has led to the modern European strain, has occurred after the Iceman’s time period and not already 10,000 years ago as previously thought. 

Dr Zink said, “These findings show that H pylori was present in humans a long time ago and most probably since the onset of modern humans. The bacteria is probably not only a pathogen, but also could have some positive effects. This was proposed in some studies that have shown that the absence of H. pylori could increase the risk for gastroesophageal reflux disease or esophageal adenocarcinoma.” He added that “doctors should consider this and think about the pros and cons of H pylori eradication.” 

During the interview with IDA, Dr Zink added that “it is important to also study the evolution and spread of infectious diseases and not only focus on the treatment of those diseases. A study like ours could help to better understand the mechanisms on how pathogens adapt to their human hosts and how they are transmitted between people and in populations. A better understanding of a pathogen can then also support and enhance a better treatment and avoidance of infectious diseases.”

Dr Zink said in EURAC’s press release that more research is needed and several are in the planning stages in South America and Asia.

References

1. Maxiner F, Krouse-Kyora B, Turaev D et al. The 5300-year-old Helicobacter pylori genome of the Iceman. Science. 2016;351 (6269):162-165.