Practitioners of "biotherapy" - or the use of living animals to treat human ailments - say science is beginning to back up their anecdotal claims that maggots, leeches and intestinal worms may be effective in the fight against everything from irritable bowel disease to allergies and psoriasis.
Now supporters hope the feds will approve something called helminthic therapy, which is the use of parasitic whipworms to battle auto-immune disorders like Crohn's disease or severe allergies. Filmmaker Sharon Shattuck featured these critters and their supporters in her new documentary "Parasites: A User's Guide."
Shattuck profiled several people whose severe allergies prevented them from going outdoors, and who believe they were cured with the use of parasites.
"These are people at their wits' end," Discovery News quoted Shattuck as saying.
"But the worms are able to tap into the inflammatory response and turn it down. It acts as a soothing mechanism."
Medical researchers like Joel Weinstock at Tufts University are trying to discover the science behind that mechanism. Weinstock says that modern society-in the quest for proper sanitation and clean drinking water-may have destroyed many of the natural intestinal parasites that evolved alongside humans.
This so-called "Old Friends Hypothesis" (first put forth in the mid-1980s) says that public health improvements in the 20th century have corresponded to a simultaneous increase in auto-immune disorders, an increase not seen in the underdeveloped world where parasites are common.
"Many of these worms are bio-engineered for humans," Weinstock said.
"We adapt to them; they adapt to us. It becomes like an organ, just like your heart, your spleen or your liver."
Weinstock says the parasites need to turn down the human's immune defenses just a tad in order to survive. But they can't turn it down too much, or both the host and parasite would die.