Talk about dedication to the job. To test the association between hookworms — intestinal parasites — and food allergies, Dr. James Logan infected himself with the suckers and swallowed a pill camera to film the action in his gut.
Tropical disease expert Dr. Logan and his team at the London School of Hygiene and Tropical Medicine (LSHTM) study how to control insects that transmit deadly diseases like malaria. The self-experiment was for a segment on the TV show Embarrassing Bodies, which debuted in the U.K. in March.
Hookworms are passed through feces and people can acquire them by walking barefoot on contaminated soil — like at the beach. Previous research has suggested that hookworms can alleviate and even cure symptoms of food allergies, which intrigued Logan who suffers from a food allergy that prevents him from eating bread without becoming ill.
“Surprisingly, hookworm infection is known to have a beneficial effect on health. Published studies have shown that hookworms can cure or alleviate allergies such as inflammatory bowel disease and food allergies and even asthma. The worms produce saliva that changes the immune system to stop your body overreacting to the things that cause allergies,” says Logan.
In the Bodies episode, LSHTM researchers injected hookworms into Logan’s skin, and over two months they traveled through his bloodstream reaching both his heart and lungs. From the lungs, the critters were coughed up and then swallowed, making their way into his intestines. As the hookworms matured, the pill camera tracked the damage and inflammation they caused to Logan’s intestines, which he described as “stabbing pains” in his gut.
Part of the motivation for the stunt was to use new technology to show how hookworm infection is acquired. “Until now, no one really knew how hookworm entered the body — they are too small to be seen with the naked eye. But, for the first time ever, we used state-of-the-art imaging to watch the worms enter my body. This gave me and the other scientists useful information about how the worms are able to achieve the incredible feat of being able to get through our tough skin,” says Dr. Logan.
(MORE: Gut Bugs: They Are What You Eat)
Tests showed that Logan had an increase of eosinophils — a type of white blood cell and a sign of immune response to worms. Although his stomach pain persisted, Logan was able to enjoy a meal of pizza and breadsticks without the nauseating side effects. “I had a brilliant night’s sleep,” he told viewers the morning after his carb-filled meal. “Maybe the worms are having a good effect on my body. I am able to do things like eat bread, which is great.”
At the end of the experiment, Logan was able to rid his body of the worms by taking the anti-worming drug albendazole.
Some onlookers thought the scientist’s self-experiment was a bit unwise. “Being a person who has spent most of my career making sure people and animals don’t get worms, it seems like this is going in the wrong direction,” says Dr. Dwight Douglas Bowman, a professor of parasitology at Cornell University. According to Dr. Bowman, hookworms have been essentially eradicated from the U.S., and experimenting with them the way Logan did makes him uneasy. “We don’t want to put other people and the environment at risk. If you give yourself too many you can get sick. They can cause serious anemia. For a successful pharmaceutical trial, you would need to test a lot of people and I don’t want to give 10,000 people hookworm,” he says.
But Logan wasn’t nervous about his own risk and says the experiment was safe: “I wasn’t nervous about having hookworms as I know that there is little risk of becoming ill. The only time people become ill with hookworms is when they are in very high numbers. And the complication then is anemia. The number I infected myself with was extremely small so there was no danger of me becoming ill.”
Dr. Quentin Bickle, a reader in parasite immunology at LSHTM who designed the study, said in a statement, “the application of novel imaging methods in the television experiment provided an interesting opportunity to find out more about hookworm skin penetration and about the balance and the link between the pathological effects of hookworm infections on the gut mucosa and the potentially beneficial effects of the modulated immune response induced.” He says further research on worm infections could shed light on our immune responses, leading to new treatments.