According to an article in last week’s Wall Street Journal, help may be at hand, or maybe we should say “stomach” for people with multiple sclerosis – as the help is courtesy of none other than parasitic worms.
Early safety studies conducted in the US suggest that the eggs of pig whipworms have anti-inflammatory properties that can reduce the size of brain lesions in MS patients. A similar trial is now under way in Denmark. And in Britain, academics at the University of Nottingham are studying the potential health benefits of hookworms.
If these trials prove successful, treatment with parasitic worms, or more correctly, helminthic therapy, could provide a simple, cheap, and controllable treatment for the debilitating condition, which affects 2.5 million people world-wide.
Multiple sclerosis is an inflammatory disease of the brain and spinal cord, in which an overactive immune system attacks the nerve fibers responsible for sending signals to the rest of the body. Its symptoms include impaired vision, muscle weakness and spasm, fatigue, memory loss and depression. Although a number of medications can slow the disease’s progression, many of them have unpleasant side effects including hair loss, muscle aches, sleeplessness and flu-like symptoms.
Interest in helminthic therapy surged in 2007 with the publication of an Argentina study which showed that the progression of multiple sclerosis was much slower in patients who carried parasitic worms in their intestines than in those who didn’t. Another recently published study in the Multiple Sclerosis Journal suggested that pig whipworm is effective in treating MS symptoms.
“The results are quite promising,” says John Fleming, a professor of neurology at the University of Wisconsin School of Medicine and Public Health, who led the study.
Five patients took part in the Phase 1 trial. All were newly diagnosed with relapsing-remitting MS, a form of the disease in which new symptoms can appear and old ones resurface or worsen. Whipworm eggs were taken from disease-free pigs and grown in a clean laboratory environment. Every two weeks over the course of three months, the patients in the study drank 2,500 of the eggs mixed into a sports drink. The eggs hatched in the patient’s intestines and were killed by the immune system after about a week. Patients who took part said the liquid was salty but didn’t taste or smell unpleasant.
During the study, patients underwent MRI scans, which tracked the number of new brain lesions that developed before, during and after they ingested the worm eggs.
“What makes us optimistic is that brain lesions in four out of the five patients decreased over the course of the study and then rebounded after it finished,” says Dr. Fleming. While the pattern shown by the MRIs is encouraging, he adds, larger and longer studies will be needed before any definite conclusions are possible.
Researchers say the Wisconsin study’s findings could mean that the immune system’s over-response to the brain tissue was lessened by anti-inflammatory effects from the worms, and this could offer an alternative approach to treating MS.
The theory behind helmintic therapy is known as “the hygiene hypothesis.” This argues that developed countries such as the U.S., Europe and Japan have higher incidences of allergies and autoimmune diseases because the population has little or no exposure to parasites or infections. In developing countries, where people are exposed to low-level infections or infestations, the rates of such diseases are much lower. Essentially, the proponents of this therapy argue, our immune system is created to be in balance with the worm’s influence on us. Naturally, our body wants to fight the foreign nematode invaders, but the worms don’t like that and they’ve actually evolved to suppress our immune response to their presence. That means that without them our immune system over-reacts to things that in its ancestral setting it would have ignored
We spoke to a friend of ours who has MS and asked, would you intentionally swallow worms if it would help control your disease? After some initial hesitation, she gave the idea the thumbs up. “Although it sounds gross, it’s probably no worse than injecting myself every day with chemicals that I really know nothing about and which leave me looking like a pin cushion” she told us.
What about you?