Pineapple and gums do have connection between them. Pineapple is a rich source of vitamin C and this vitamin helps fight a lot of diseases and disorders in a human body. If you have problems related to gum, then pineapple is one option to fight against it as it is a common antioxidant and thus helps your body to a greater extent in fighting bacteria and other toxins which create gum problems. Also pineapple helps fight diabetes and other sugar related diseases in your body.Also it helps in making bones stronger and better, so I guess it also helps in keeping your teeth strong.