AOR Mastica Chios - Helps relieve heartburn. Chios gum mastic is the resinous extract of the mastic tree. Research supports gum mastic's contribution to gastrointestinal health through its effects on unfriendly bacteria in the stomach. Mastic gum has proven useful for fighting gastritis and heartburn as well as overall gastric and intestinal inflammation. Studies have found that supplementing with mastic gum not only relieves the symptoms of these painful conditions but can actually help heal the stomach, possibly by killing H. pylori bacteria. Mastic gum is an excellent natural alternative for those who have experienced the negative long-term side effects of antacids, proton pump inhibitors, antibiotics and other medications that treat the symptoms of heartburn but not the cause.