This is what I found in the internet.
(I thought it would be OK, because my favorite yogurt (Brown Cow) includes it and they are totally against artificial stuff.)
Inulin is major constituent of some of the most famous of the "old-standby" herbs, such as burdock root, dandelion root, elecampane root, chicory root, and the Chinese herb codonopsis. Botanically, inulin is a storage food in the plants of the Composite family... It is not digested or absorbed... Inulin is recommended sometimes for diabetics; it has a mildly sweet taste, and is filling like starchy foods, but because it is not absorbed, it does not affect blood sugar levels. Despite the similarity of its name to insulin, inulin has no connection with that hormone either chemically or through physiological activity.