Parasites are those organisms that gets nourishment or in some other way benefits at the expense of its host. Sometimes the benefit could be mutual both for the host and parasite. Parasites are in fact of great help to the humans that removing them from modern life can actually affect human health.
Parasites are in one way helpful to the farmers in warding off the insects that attack the crops. The use of chemical insecticides that harm not only the bugs but indirectly the human health as well could be avoided as parasites can kill bugs. For example, small lice like aphids are known to be one of the most harmful pests faced by fruit and vegetable farmers. An effective and healthy way to destroy aphids is by aphidius ervi parasite. This parasite lays an egg in them and after the egg hatches, the larvae consume the aphids from inside out.
Research is also being done to ascertain if parasites can control autoimmune diseases especially inflammatory bowel disease. Autoimmune diseases are those caused by the body’s immune system which responds abnormally to create antibodies that can actually affect the organs of the body. This type of treatment using parasites is called worm therapy.
Though not yet proved, some intestinal worms are known to cure allergies. For instance, Hookworms are known to cure asthma and allergies. In fact the lack of childhood exposure to bacteria and parasites may lead to increased incidents of allergies and autoimmune diseases in adults. Thus humans, plants and animals do seem to benefit from the world of parasites.