It gets rid of parasites in the intestinal tract. A researcher told me that a little of the DE gets into the blood and that the DE has been known to get rid of heart worms (like dogs get, but sometimes people get also), but that it takes 6 months of faithfully taking enough DE to kill the heart worms. Since DE is roughly 85% silica, it must be the silica that is poisonous to parasites in addition to the DE simply slicing and dicing them inside of the intestinal track. The wolf sanctuary website says people need to take 2+ tablespoons of DE a day since the recommended amount of DE for a 100 lb dog is 2 Tablespoons, and most adult humans weight or than 100 lbs.