"During the Stone Age, rubber from the damar tree was used as an adhesive material. Through sediment age analysis at the site of the rubber lump discovery, researchers estimate that the gum originated from an age range of approximately 9,540 to 9,890 years ago."

To ensure that the rubber clump was truly chewed by humans, researchers compared the microbial DNA sequences within the rubber to the saliva microbiome from both modern and ancient times. The analysis results revealed an increase in the number of bacteria associated with gum disease, such as Treponema denticola, Streptococcus anginosus, and Slackia exigua.