While many species of the amoeba which live in our gut are beneficial, some are more harmfull. An excample of this is Entamoeba histolytica. This species had evolved a cellular toxin which it uses to feed on the body's own cells, rather than the nutrients which pass through the intestine. By means of causing a rapid influx of calcium into the affected cell, the organells break open and the cell is killed. The amoeba may now eat the dead cell or absorb the nutrients released as it breaks open.