Download this page in PDF format. Mastic gum is a resinous extract from the Pistacia lentiscus tree, indigenous to the Mediterranean islands. Historically, mastic gum has had many commercial uses, dating as far back as the Greek Empire where it was used as a form of chewing gum.It traditionally has been used as a treatment for dyspepsia and other disorders of the digestive tract.astic gum has been shown in a recent study to apparently inhibit growth of H. pylori as well as act as an antibiotic against the bacterium. Mastic gum recently has been tested against ulcer formation and healing in various models. One study involved experimentally induced gastric and duodenal ulcers in rats.