Wriggle room

Scientists are lifting the lid on the potential of human hookworms to treat autoimmune and inflammatory conditions.

- Nicky Pellegrino

Infecting yourself on purpose with parasitic intestinal worms may not seem like the healthiest thing to do. But a growing number of New Zealanders are doing just this, convinced that helminth therapy is the answer to managing the symptoms of a wide range of autoimmune and inflammatory conditions.

These self-treaters buy the larvae online, usually paying with bitcoin, and use a skin patch to apply them. The creatures burrow into their skin, then travel in the bloodstream to the lungs. Eventually they are coughed up and swallowed, and their journey ends in the intestine, where they attach themselves to the wall of the gut and live happily.

There is an ick factor to all of this, but also no shortage of anecdotal reports that it is an effective treatment.

"When you talk to these people, it's hard not to believe in it," says gastroenterologist Tom Mules. "They are so passionate, and clearly it's made them feel better. But that's not really how medical practice works. We need a proper evidence base to make sure it's safe and effective before we start putting it into patients on a bigger scale."

At Wellington's Malaghan Institute, Mules leads a team that is busy exploring the therapeutic potential of human hookworms. The theory is that we co-evolved with these parasites over millions of years, and that by eradicating them in the developed world, we may have sparked a rise in autoimmune and inflammatory disease.

The science is showing that having a colony of hookworms in our gut seems to affect us in multiple ways. Perhaps most significant is that these parasites are able to manipulate their host's immune system.