Gum Arabic is considered the richest natural source of prebiotics, up to 85%. Also known as Acacia Gum, it is a natural gum made of hardened sap taken from two species of the Acacia tree; Acacia Senegal and Acacia Seyal. The best quality comes from Acacia Senegal. It is the only plant so far that has the highest amount of prebiotics that comes in the form of soluble fiber. read more..