Fibiger, Johannes Andreas Grib, FEE buh guhr, yoh HAH nihs ahn DREH ahs greeb (1867-1928), was a Danish bacteriologist. He won the 1926 Nobel Prize for physiology or medicine. He produced stomach cancer in rats by feeding them cockroaches infested with nematodes (small worms). The nematodes provided a means of producing cancer experimentally. Fibiger was born in Silkeborg, Denmark.