Burdock is great for you. It is very high in a fiber called inulin . Inulin is good for you because it passes through your stomach and small intestines undigested and is consumed by the microflora bacteria in your colon (large intestine). Those good bacteria in your colon help get rid of bad bacteria which prevent infections and stimulate your immune system function.
Burdock, in particular the skin of the roots, is very high in the antioxidants chlorogenic acid (CHA) and caffeic acid (CA) . These are important because antioxidants remove the excess free radicals from your body. Free radicals cause damage to your cell membranes and DNA which can lead to cancer .
If you cannot collect burdock plants in the wild you can try purchasing some whole dried burdock roots from an herb store. I personally use this in hand made supplements and in herbal tea blends.