Scientists thaw 5,300-year-old mummy to study ancient gut bacteria

Scientists say the famous "Iceman," a 5,300-year-old European mummy, may have been feeling a little ill on the day an unknown assailant chased him through the Alps, shot an arrow into his artery and killed him.

See Full Article

A recent study shows the Copper-Age European, who is also known as Oetzi, carried a viral strain of Helicobacter pylori bacteria in his stomach, a discovery that scientists say sheds important light on both the Iceman's health and the history of human migration.

The findings were published in the journal Science on Thursday.

According to the study authors, Helicobacter pylori is one of the most common and ancient human pathogens.

Scientists estimate the bacteria has been infecting humans for at least 100,000 years. But researcher say the Iceman sample is the oldest Helicobacter pylori DNA they've ever examined in depth.

"That is why this genome is so special," study co-author Yoshan Moodley, a genetics and biology professor at South Africa's University of Venda, told reporters in a teleconference on Wednesday. "It allows us this absolutely unique window into the Copper Age. We don't have to infer it. We can see."

Helicobacter pylori can cause ulcers or gastric carcinoma, but fewer than 10 per cent of carriers actually suffer from these symptoms.

Because of this, it's unknown if Iceman actually felt the effects of his bacterial infection.

"We can't be 100 per cent sure that he really suffered from gastric disease," Moodley said. "We have clear evidence that he had immune reactions, but we can't really say to what extent."

Thawing the Iceman and extracting the samples

The Iceman's remains are usually kept in Italy's South Tyrol Museum of Archeology, where the museum imitates the Alpine conditions in which the body was preserved until hikers found it in 1991.

But in order to extract and examine bacteria from the Iceman's stomach, scientists had to temporarily thaw the mummy.

Researchers did this in a tightly controlled environment, the Iceman wasn't harmed in the process and he was later refrozen, says study co-author Albert Zink, the scientific director at the Institute for Mummies and the Iceman.

Once the body was defrosted, researchers accessed the stomach through a previously-made incision, and extracted samples from his gastrointestinal tract.

In these samples, they found the presence of Helicobacter pylori, and were able to reconstruct the bacteria's genome and examine its genetic makeup.

This analysis, the study says, led to a "surprising" new understanding of ancient Europeans' origins.

Using Helicobacter pylori to trace human migration

Because Helicobacter pylori has existed in humans for so long, scientists say its evolution reflects the way human populations have grown, migrated and changed.

"Helicobacter pylori's worldwide population structure is almost literally a mirror image of human populations," Moodley said. "So we use them as a surrogate for what humans were doing at various stages of prehistory."

Modern strains of the bacteria are categorized according to geographic location, and can be traced back to different ancestral sources.

The modern Helicobacter pylori strain in Europe, for example, comes from a combination of ancestral bacteria from Asia and Africa.

But scientists were surprised to find that the ancient bacteria in the Iceman's stomach showed only the Asian strain, not a mixture with the African variation.

Scientists say this suggests a wave of human migration arrived in Europe from Africa sometime after the Iceman's death, introducing the North African strain of bacteria to the population.

"The wave of migration that brought the African Helicobacter pylori into Europe had not occurred, or had not occurred in earnest, by the time the Iceman was alive," Moodley concluded.

'Paleomicrobiology' and examining other mummy guts

Now that scientists have successfully extracted and reconstructed bacteria from the Iceman, they hope to use similar techniques to explore other ancient gut bacteria.

"One thing we definitely want to do is to expand our investigation to other mummies," Zink said on Wednesday.

He said he and his co-researchers have already been in touch with colleagues in Northern Europe, South America and Asia, and also hope to trace the paths of ancient bacteria in Siberia.

Eventually, Zink said, he hopes this could open the doors to a "totally new" field of research, which he dubs "paleomicrobiology."



Advertisements

Latest Tech & Science News

  • 'Selfish' beachgoers blamed after stranded baby dolphin dies

    Tech & Science CTV News
    A baby dolphin died after becoming stranded on a beach in Spain and an animal rescue group is blaming a crowd of spectators for exacerbating the danger by touching and photographing the vulnerable marine mammal. Source
  • SpaceX successfully delivers experiments, treats to space station

    Tech & Science CBC News
    A SpaceX shipment arrived at the International Space Station on Wednesday, delivering a bonanza of science experiments. The SpaceX Dragon capsule pulled up following a two-day flight from Cape Canaveral. NASA astronaut Jack Fischer used the space station's hefty robot arm to grab the Dragon 400 kilometres above the Pacific, near New Zealand. Source
  • SpaceX Dragon delivers scientific bounty to space station

    Tech & Science CTV News
    CAPE CANAVERAL, Fla. -- A SpaceX shipment arrived at the International Space Station on Wednesday, delivering a bonanza of science experiments. The SpaceX Dragon capsule pulled up following a two-day flight from Cape Canaveral. Source
  • A Killam Prize winner's top 5 ideas for getting more women in STEM

    Tech & Science CTV News
    Molly Shoichet knows a thing or two about overcoming gender barriers in science, technology, engineering and math (STEM). The 2017 Killam Prize winner is an engineering superstar who oversees more than two dozen people at a University of Toronto lab that is working on everything from curing blindness to strokes. Source
  • U.K.'s new flagship aircraft carrier arrives at home port

    Tech & Science CTV News
    LONDON -- Britain's new flagship aircraft carrier HMS Queen Elizabeth arrived at its home port in southern England on Wednesday to great fanfare as tens of thousands jammed the harbour in welcome. Sailors lined the flight deck as the 3 billion-pound ($3.87 billion) aircraft carrier arrived at Portsmouth Naval Base. Source
  • New U.K. aircraft carrier HMS Queen Elizabeth arrives at port

    Tech & Science CTV News
    LONDON -- The HMS Queen Elizabeth, the biggest ship ever built for the British navy, sailed into its homeport for the first time Wednesday as tens of thousands jammed the harbour to welcome it. The 3 billion-pound ($3.9 billion) ship arrived at Portsmouth Naval Base in southern England with sailors lining the flight deck and Royal Navy helicopters soaring above. Source
  • Egypt archeologists discover tombs dating back 2,000 years

    Tech & Science CTV News
    CAIRO - Egypt's antiquities ministry says that archeologists have discovered three tombs dating back more than 2,000 years, from the Ptolemaic Period. The discovery was made in the Nile Valley province of Minya south of Cairo, in an area known as al-Kamin al-Sahrawi. Source
  • Cyberattack cost hundreds of millions: world's biggest shipper

    Tech & Science CTV News
    COPENHAGEN, Denmark -- The June cyberattack that paralyzed the computer systems in companies around the world is estimated to have cost the world’s biggest container shipping line between $200 million and $300 million, A.P. Moller-Maersk said Wednesday. Source
  • 'Robophobia' a growing concern amongst humanity

    Tech & Science CTV News
    CINCINNATI - Robots are secretly plotting to kill us. Or enslave us. Or, at best, they will take our jobs, one by one. From science fiction written by Isaac Asimov eight decades ago to "Dilbert" cartoons today, the relationship between robots and humans has long fascinated - and worried - people. Source
  • Canadian food inspectors using DNA technology to test health of fruit plants

    Tech & Science CTV News
    VANCOUVER - Canada's agriculture minister says using DNA-based technology to test the health of fruit plants will grow Canada's agricultural export sector. Lawrence MacAulay announced Tuesday that the Canadian Food Inspection Agency is leading two projects with multiple industry and research groups where new science will be used to find faster ways of determining if fruit plants are infected with viruses. Source