Protein Secreted by Parasitic Worms May Treat Crohn's and Colitis

A recent study reported that a protein secreted by parasitic worms can help prevent immune cells from stimulating inflammation, thereby treating inflammatory bowel diseases (IBD) such as Crohn’s disease and ulcerative colitis.

It is a well-known fact that bacteria help maintain a natural balance of immune responses within the bowel by regulating bowel activity. Several studies have also found that fungi play a vital role in regulating bowel activity.

The new study

The study, published in the journal Nature Communications, was conducted by researchers at Edinburgh and Glasgow universities. The researchers’ findings suggested that an infection by Heligmosomoides polygyrus, a worm parasite or helminth, can alter the natural balance of the bacteria within the gut and prevent inflammatory signals within the bowel. They found that these types of parasites produce a protein that is remarkably similar to the human transforming growth factor beta, known as TGF-β. This protein is known for assisting in the activation of regulatory T-cells, known as Tregs. Tregs are a subgroup of immune cells and they help ensure that reactive T-cells are kept under control.

“Discovering a new protein that can potently induce regulatory T cells (Tregs) from human cells is unexpected and very exciting in terms of finding a new potential biologic for inflammation conditions,” said Danielle Smyth, lead author of the study. “We hope to explore this option and see whether the Tregs our parasite molecule induces offer a regulatory advantage over current treatments,” she added.

The researchers’ findings also support the theory that worms and other microorganisms can help protect a patient from over-reactive immune responses that are known to cause allergies and diseases. Therefore, stimulating such protective mechanisms may help treat patients without causing common side effects associated with immunosuppressant medications. “The next horizon … will be to test whether the new protein can be used to treat inflammatory diseases, reaping the benefits of the ‘hygiene hypothesis’ and dispensing with the parasites themselves,” said Rick Maizels, a parasitology professor at Glasgow university.

Parasitic worms have been studied before

This study is not the first to be conducted on the subject of parasitic worms and their role in easing symptoms associated with inflammatory bowel diseases. In another recent study, published in the journal Science Translational Medicine, researchers followed a 35-year-old man who had infected himself with Trichuris trichiura, the human whipworm. For this particular patient, who was diagnosed with ulcerative colitis, the worms seemed to help ease his symptoms by prompting healing instead of inflammation.

He then contacted P’ng Loke, a parasitology professor at New York University’s Langone Medical Center. “When I heard what he had done, I thought he was crazy,” said Loke. Yet, the professor agreed to track his progress as he had known earlier reports that suggested individuals received relief from doing this sort of thing. “When he had colonoscopies for different reasons, we basically tried to characterize biopsies that were taken from his gut. We tried to look at these biopsies and see what kinds of immune cells were activated… what kind of genes were activated. We were trying to put together a picture of what was going on in the gut at different times,” said Loke.

Read on to learn more about the potential relationship between parasitic worms and IBD.