Swedish researchers are investigating whether Ötzi, the 5,300-year-old mummified iceman, may have had resistant bacteria in his body at the time of his death. Svenska Dagbladet can today reveal that Ötzi’s body was defrosted in November, enabling samples to be taken from his stomach and large intestine. Stockholm-based researchers are currently analysing specimens obtained by Lars Engstrand, a professor of infectious disease epidemiology.

Next September marks the 20th anniversary of the spectacular discovery by two tourists of a frozen male body in a glacier in the Ötztal Alps, a mountain range on the border between Austria and Italy. News of the find quickly became a global sensation. The mummified human body, found in a mountain crevice 3,200-metres above sea level, was the oldest ever discovery of its kind. What’s more, the body was extremely well preserved.

Ötzi, as the mummy became known, is held at the South Tyrol Archaeological Museum in northern Italy. Normally the body is covered in a thin layer of ice to keep it in good condition. Recently, however, it was defrosted for research purposes for only the second – and perhaps the last – time.

On November 8, experts from several different countries spent six hours examining Ötzi’s brain, lungs, prostate and stomach. One of the researchers present in Bolzano when the body was defrosted was Lars Engstrand, a Swedish professor from Stockholm’s Karolinska Institutet who also serves as head of the Department of Bacteriology at the Swedish Institute for Infectious Disease Control. A specialist in clinical bacteriology, he has previously conducted extensive research on bacteria that cause stomach ulcers.

In an exclusive interview with Svenska Dagbladet, Engstrand explains how he got to spend two hours studying Ötzi’s stomach alongside professors Peter Malfertheiner from Germany and Francis Megraud from France.

First the scientists attempted to deploy a modern endoscope to aid them in their investigations, inserting the viewing device down Ötzi’s throat. But when the opening proved too narrow, the scientists decided instead to slice open the iceman’s abdomen.

“We made a hole, around 10 centimetres wide, and picked out food he had eaten 5,300 years ago. His stomach looks exactly the same as a modern person’s except it’s a bit drier and more crumpled. It’s incredibly well preserved,” says Lars Engstrand.

The professor took some 20 samples from Ötzi’s stomach, large intestine, and from a periodontal pocket[P2] . The test tubes were then transported to Sweden for analysis at the Swedish Institute for Infectious Disease Control and Karolinska Institutet.

Molecular biologist Annika Fahlén last week began conducting DNA analysis of the iceman’s stomach bacteria – and the initial results are promising. The DNA from Ötzi’s bacterial flora remains intact to such an extent that scientists will be able to determine, with the aid of modern technology, which bacteria he was carrying at the time of his death.

“I’m surprised it’s so well preserved considering how tremendously old it is, but that’s a result of the body being frozen. We’re going to be able to check Ötzi’s bacterial DNA against a database, which will allow us to identify the bacteria he has in his stomach,” says Fahlén.

The contents of Ötzi’s stomach will also be examined with an optical microscope and an electron microscope. Among Lars Engstrand’s samples is a mucous membrane specimen taken from the iceman’s stomach.

“We cut fairly large pieces out of the stomach lining. This is valuable because it enables us to see if he had an inflammation of the stomach,” says Engstrand.

The Swedish researchers expect the first test results to be ready in March. If all goes according to plan, the experts who examined the defrosted Ötzi will be able to present their findings in scientific journals before the 20th anniversary of his discovery next autumn.

Lars Engstrand is hoping his analysis will provide answers to three questions with potentially exciting consequences for the future of gastric research:

* What kind of bacterial flora existed in the human stomach and intestines 5,300 years ago?

* Was the iceman a carrier of bacteria that cause stomach ulcers?

* Were there any resistant bacteria in Ötzi’s stomach?

Engstrand regards the issue of resistant genes in bacteria as being of significant interest since it could well contribute to the development of more effective antibiotics.

“What we see when we examine Ötzi will perhaps improve our understanding of the development process of bacteria that are resistant to antibiotics. That’s what we’re hoping for,” says Lars Engstrand.

According to the researchers’ theory, the iceman’s stomach will contain bacteria with antibiotic resistance genes. Their hypothesis is based on earlier discoveries of resistance genes in soil bacteria not exposed to antibiotics.

“We’ve never before had a human sample from that time but now we do. We want to examine how genes adapted after bacteria became exposed to antibiotics. It’s possible that this may be of use when developing new strains of antibiotics.”

Lars Engstrand is proud of the fact that researchers from Sweden are involved in analysing the iceman’s remains. In his view, the opportunity has arisen partly as a result of Karolinska Institutet receiving funding to invest in modern DNA analysis equipment.

But he has also personally pressed for years to be given access to Ötzi’s stomach. His quest to take bacteria samples from the iceman began at a conference in Munich in 1994. It was there, three years after the Alpine discovery of the strange mummy, that Engstrand sat down for a beer with his German research colleague Peter Malfertheiner and declared that he “had to get into the iceman’s stomach at some point”.

After 16 years of nagging, and with the help of Peter Malfertheiner’s contacts in Bolzano, the opportunity eventually arose when Ötzi was to be defrosted for a second time. Lars Engstrand describes how his pulse started racing when he finally got to enter the refrigerated room and observe the defrosted body.

“It was incredibly fascinating. I felt really humbled by the experience of being able to examine someone who has been dead for 5,300 years.”