Really Old Chewing Gum Reveals Clues

Scientists at the University of Copenhagen successfully extracted a complete human genome from ancient ‘chewing gum.’ Their success may mean there is a new untapped source of ancient DNA.

While excavating in Lolland, Denmark, archaeologists found a 5,700-year-old piece of birch pitch, which was often used as ‘chewing gum’ in ancient times.

The extraction is the first time that an entire ancient genome has been extracted from anything other than human bone tissue.

Not only did researchers extract a complete human genome, but they also were able to retrieve DNA from oral microbes and several other important human pathogens.

The research is valuable because it gives scientists a look into a period when no human remains have been recovered.

Based on the collected DNA, researchers found that a female chewed the birch pitch. They were also able to discern that she was genetically more closely related to the hunter-gatherers from mainland Europe than those who lived in central Scandinavia where she was found.

Based on the found DNA, scientists also found that she was likely to have dark skin, dark hair and blue eyes.

The birch pitch was found during a dig at Syltholm, an ancient village east of Rødbyhavn in southern Denmark. Syltholm is a unique dig site, with nearly everything sealed in mud – which translates to high levels of preservation of artifacts.

Bacterial Evolution

High levels of preservation mean that researchers can more readily extract and identify pathogens found in the oral biome that can offer clues about the diet and health of ancient peoples.

One of the pathogens found in the DNA resembled the Epstein-Barr virus, which is known to cause infectious mononucleosis or glandular fever.

Biomes Today

Today, researchers are still using the oral biome to reveal clues about oral health.

‘We can tell a lot about a patient and their habits through a checkup,’ said Dr. Clara Griffey, a Waco, Texas, dentist.

Some of the things dentists can see when they look into the mouths of their patients include if the patient is brushing and flossing regularly, if they grind or clench their teeth or if they have diabetes.

‘If patients are clenching or grinding their teeth at night, the evidence will show up in the form of worn-down, cracked or fractured teeth,’ Griffey said.

In some cases, the patient may not even be aware of their behavior.

‘It is amazing what the mouth can reveal,’ Griffey said.

Source: Scientific American. Ancient ‘Chewing Gum’ Reveals a 5,700-Year-Old Microbiome. 17 December 2019.