Inulin is a type of fiber that's found in certain plant foods. Chicory root is the main source of inulin in supplement form. Chicory was originally found in Europe and Asia. Egyptians grew it thousands of years ago as a medicine.any foods -- and plants that are less commonly eaten -- contain inulin. These include: 1  Asparagus. 2  Bananas. 3  Burdock. 4  Chicory, which is used in salads.