“If you look at the data that comes in from immunological studies ... where you remove the parasites [that’s] where you see the highest incidence of autoimmune diseases and allergies,” said Severine Navarro, the paper’s lead author and a senior research fellow in Loukas’s lab at James Cook University in Australia.

Many parasites have evolved the ability to hide from their host’s immune systems. When a hookworm crawls into a human, it secretes chemicals that turn off the immune alarm bells and repair the tissue around it. It limits its consumption of blood to a few drops a day and doesn’t leave its offspring scattered all over its host’s gut. (Instead, it thoughtfully plants them in the host’s poop to ensure an orderly exit from the body.) Like a very conscientious cat burglar, the hookworm knows it’s best served by not making a mess.

“It’s almost symbiotic,” Navarro said, “because in order for it to survive and thrive, it needs its host to be happy and healthy.”

This is fascinating. I'm sure people with chronic asthma and allergies would give this a go in a heartbeat.