A 10,000-year-old piece of chewing gum is offering an insight into Scandinavia's first human settlers.

Key points: DNA belonging to three people was discovered in the tar of a birch bark tree, which ancient settlers chewed

DNA belonging to three people was discovered in the tar of a birch bark tree, which ancient settlers chewed The material was discovered in the early 1990s, but DNA analysis had not been possible until recently

The material was discovered in the early 1990s, but DNA analysis had not been possible until recently Researchers say the gum provides "enormous potential" for tracing the origin and movement of early humans

Archaeologists have extracted DNA belonging to three people — two women and one man — from the tar of a birch bark tree, which ancient settlers both chewed and used to fix arrowheads onto arrows and blades onto axes.

The material was discovered in Huseby-Klev, an early Mesolithic hunter-fisher site on the Swedish west coast, in the early 1990s, but DNA analysis had not been possible until recently.

According to researchers, it is the oldest human DNA sequenced from the area so far.

"Much of our history is visible in the DNA we carry with us," said Anders Gotherstrom from the Archaeological Research Laboratory at Stockholm University, where the work was conducted.

"So we try to look for DNA wherever we believe we can find it."

The results revealed the trio's DNA was found to share a close genetic affinity to other hunter-gatherers in Sweden and to early Mesolithic populations from Ice Age Europe.

However, tools found at the same site where the gum was unearthed were a part of lithic technology brought to Scandinavia from the East European Plain — otherwise known as modern-day Russia.

Researchers now hope the chewing gum will help fill in historical gaps, including who helped make the Stone Age tools, what Scandinavia's first human settlers ate and what bacteria lived in their teeth.

The ancient gum with two plastelina casts for each side capturing several teeth imprints. ( Supplied: Stockholm University )

"DNA from these ancient chewing gums have an enormous potential not only for tracing the origin and movement of peoples [a] long time ago, but also for providing insights in their social relations, diseases and food," said Per Persson at the Museum of Cultural History in Oslo.

The findings have been published in the journal Communications Biology.