Before toilets with running water were common in human homes -- which actually wasn't that long ago -- pretty much everyone had a worm or two living in their intestines. And new research suggests that some of them might have actually made us healthier.

According to a recent report by Dr. William Parker, a researcher and Associate Professor of Surgery at Duke University, while some parasitic intestinal worms, like the porcine tapeworm and the human hookworm, can make humans sick and even kill them, researchers now know that some types of intestinal worms are actually beneficial to their hosts -- and may help the human body combat everything from allergies to multiple sclerosis.

Dr. Parker's own research found that the presence of intestinal worms, or helminths, in pregnant rat mothers protected their unborn babies' brains from inflammation.

Dr. Parker also pointed out that "Helminths have been found to protect laboratory animals from a wide range of allergies and autoimmune conditions," that "recent findings suggest that many types of cancer can be reduced by helminths," and that "In controlled studies in humans, helminths were shown to halt the progression of relapsing remitting multiple sclerosis and effectively treat many individuals with inflammatory bowel disease without report of adverse side effects."

So how does this all work? Dr. Parker states that "mutualistic helminths help regulate immune function, stimulating our body to build regulatory networks of immune cells that decrease general inflammation without hurting our immune system’s ability to respond to danger."

In other words, the presence of friendly intestinal worms forces our immune systems to be active and step up their game without harming them, which makes them stronger and better at fighting off the inflammation that can lead to certain illnesses. Dr. Parker also notes that the presence of the worms can make the bacterial ecosystem in the gut healthier, which can lead to better overall health.

No intestinal worms are currently approved by the FDA, but Dr. Parker and other researchers found that some people have already begun taking matters into their own hands by buying worms and swallowing up to 30 of the critters per month to treat everything from migraines to depression... which can be risky, since the worms are currently unregulated.

"Thousands of people are using helminths to self-treat a vast array of inflammation-related conditions, from inflammatory bowel disease to hay fever to multiple sclerosis to migraine headaches," Dr. Parker reported. "Part of our study included a survey of helminth users, and most people filling out the survey reported that helminths treated their inflammatory conditions more effectively and with fewer side effects than did pharmaceuticals."

"While work in labs, and our own research on people self-treating with helminths is promising, the safety and effectiveness of helminths needs to be evaluated in more clinical trials," Dr. Parker concluded. "We can’t let the ick factor intestinal worms may initially inspire hold us back from further research."