Up for approval Detlev Goj

More than 7000 people worldwide are thought to have bought parasitic worms online and ingested them in an attempt to treat conditions ranging from depression to inflammatory bowel disease. Now, a type of pig worm is being evaluated for approval as a food ingredient in Germany. If accepted, it will become the first officially approved product of its kind in Europe.

The idea for intentionally infecting yourself with parasites is that, until recent improvements in hygiene, they were common inhabitants of our bodies, having evolved to secrete substances that pacify our immune systems, so they can live in our guts. Detlev Goj, of Thai company Tanawisa, thinks that, in eliminating the problem of parasites – particularly the human hookworm – we may have overlooked possible benefits some parasites may have.

Hookworms are bad – they can cause diarrhoea, pain, anaemia and weight loss. Thankfully, they are no longer a common problem in rich nations. But parts of the world where parasitic worms are still common haven’t had the same rises in immune conditions like allergies, inflammatory bowel problems, type 1 diabetes and multiple sclerosis that have been seen in richer nations.


“Most research has been focused on hookworm disease, and we’ve overcome that but overshot slightly,” says William Parker of Duke University Medical Center in Durham, North Carolina. “We need to scale back and find a happy medium.”

Hookworm alternative

To avoid the downsides of the human hookworm, Goj’s team have been looking for parasites in other animals that may cause milder infections in people, while also helping to calm our immune system. They settled on the pig whipworm (Trichuris suis). This parasite’s eggs can survive passage through the stomach, with larvae emerging in the caecum, a pouch-like region of the gut where the small and large intestines meet.

Because these worms are adapted to living in pigs, they can’t survive for very long in humans. When the team tested them as a possible treatment for the intestinal condition Crohn’s disease, they found no evidence of the worms reproducing, and the parasites were only visible in colonoscopies for a short period after ingesting the eggs. Together, this suggests the worms are probably starving to death and being digested within a month.

After promising, small studies, Goj and colleagues ran a large, placebo-controlled trial of pig whipworms as a treatment for Crohn’s disease, but it was stopped early by a monitoring committee after participants showed no benefits within three months. Goj believes this was too soon, partly because it takes 20 weeks or longer for the benefits of worms to kick in.

Nevertheless, Goj’s team did get a whipworm product approved in Thailand in 2012, on the basis that it is a natural product and tests had found no ill-effects. This helped fuel growing demand online for approved and unapproved parasite products. When Parker surveyed self-treaters, their doctors and online suppliers of parasitic worms in 2015, he calculated that around 7000 people were giving themselves worms worldwide, to treat a wide range of autoimmune and mental health conditions.

Read more: I tried ingesting rat tapeworm parasites and my poo turned green

“Self-medication with any type of worm is not recommended and it is important to remember they’re not in any way completely harmless, and may cause quite severe side effects if not monitored very carefully by a doctor,” says Helena Helmby at the London School of Hygiene and Tropical Medicine.

Mixed response

However, a range of trials with various kinds of live worms have been conducted or are in progress, says Gabriele Sorci at the University of Burgundy, France, and the results seem to indicate that such infections can alleviate the symptoms of inflammatory diseases.

Now Germany’s Federal Office of Consumer Protection and Food Safety has accepted Goj’s whipworm product for official evaluation. If approved, it could be legally sold in high street shops, and it may then go on to be approved by other European Union member states, making it the first live worm product approved for sale as a food ingredient in Europe.

“This is the first live worm product to get this far,” says Goj. He hopes to sell small vials of the product, each containing 500, 1000 or 2500 eggs of the pig whipworm, to be consumed in food or drink.

Unlike medical drugs, novel food ingredients don’t need to be shown to work in a particular way for approval in the EU – all that is needed is evidence that they are safe. So the question of whether such worms really can treat autoimmune disorders remains open.

The application has been met with a mixed response. “In my opinion, worm therapies belong in the same category of pseudoscience cult therapies as chelation therapy for autism,” says Peter Hotez of Baylor College of Medicine, Texas. He suggests that approving live worm or worm egg treatments in Germany would be a “dumb idea”.

“It would be better if we had more studies, but I’m actually not terribly concerned about this,” says Aaron Blackwell at the University of California, Santa Barbara. He says dangerous side effects might be possible if, for example, worms are able to move out of the gut into other parts of the body, but this is very rare. “Probably, taking these eggs may be no worse than many other dietary supplements that many people use regularly,” he says.

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