Gut bacteria—microbes that lie in the human intestine and help with digestion—are actually a sign of good health. In fact, when these microbes go away it can cause illness. Antibiotics, which kill beneficial as well as harmful bacteria, can cause health problems this way. Colitis, for example, seems to be associated with intestinal flora that are absent or not functioning. Fortunately, there may be a way to restore these bacteria and treat certain types of colitis: the eggs of certain types of parasitic worms, or helminths. are being researched as a treatment for colitis.
A type of helminth known as whipworm is estimated to infest one billion human beings, mostly in tropical areas. It can cause bloody diarrhea, leading to anemia and vitamin A deficiency. In severe cases, the wall of the rectum falls down, causing incontinence. However, whipworm is harmless in many cases, and can even provide some benefits, for example, by giving an overactive immune system something to attack.
Inflammatory bowel disease is most common in wealthy regions of the world. Those are the same areas where whipworm and other helminth infections are lowest. For example, in the United States, parasite infestations are highest in poor areas of the rural South, where climate and economic factors are especially favorable to parasite growth. Researchers suggest this isn’t a coincidence. Helminth treatment experiments in mice have shown that parasites can redirect immune system resources from the bodies organs, and even induce the body to repair the damage.
“The idea for treating colitis with worms is not new, but how this therapy might work remains unclear,” said NYU microbiologist P’ng Loke, PhD, an author of the study, in a statement. “Our findings suggest that exposure to helminths may improve symptoms by restoring the balance to the microbial communities that are attached to the intestinal wall.”
The researchers used the parasites to treat otherwise intractable chronic diarrhea in monkeys. The diarrhea often occurs in the animals, which are kept for research purposes. Researchers are in the process of starting human trials.