Tiny fish nibbling on pieces of human skin. Maggots liquefying and eating dead tissue. Leeches sucking blood. Worms winding through a person’s insides.

Does this sound like the plot to a B grade horror movie or the newest gross-out reality show?

Believe it or not, these are actually medical "prescriptions" currently being studied by serious scientists and already in use by some doctors to help certain patients with difficult-to-treat conditions.

Sure, the idea of having leeches, maggots, worms, or other creatures on or in your body is enough to make most of us feel a little ill, even if we are perfectly healthy. But these unusual -- and in some cases ancient -- healing techniques have restored healthy circulation to dying tissue and even conquered infections resistant to modern-day antibiotics in cases that high-tech medical treatments have failed to cure.

Biotherapy to the rescue

There’s a word for these therapies and, no, it isn’t "EWWW!" Instead, it’s biotherapy. The non-profit Bio Therapeutics, Education and Research Foundation (www.bterfoundation.org) defines biotherapy as the use of live animals to aid in the diagnosis or treatment of illness.

While biotherapy includes familiar animal helpers like guide dogs, it also includes these forms of more unusual creature therapies:

• Hirudotherapy treats wounds with leeches.
• Maggot debridement therapy (MDP) removes dead tissue from wounds.
• Ichtiotherapy uses certain species of fish to treat wounds and exfoliative skin conditions like psoriasis.
• Helminthic therapy uses deliberate infection with worms to treat immune-mediated disease.

Biological medical devices

In 2004 the Food and Drug Administration (FDA) gave two of these creepy, squirmy therapies the same designation as pacemakers and prosthetics. Leeches and maggots became the first live animals to be officially FDA-approved as medical devices.

So what specifically is it about these creatures that have earned them such medical respect?

Leeches, bloodsucking relatives of the earthworm, were used by healers for bloodletting from the time of Hippocrates in ancient Greece until the 19th century. Doctors finally decided bleeding sick people with leeches didn’t necessarily make them feel better and often made them worse.

But modern-day doctors have figured out that using leeches actually do have medical uses if used appropriately -- specifically, the creatures can suck blood out of grafted tissue so that new veins can grow more easily. At the University of Michigan, for example, doctors have used leeches to help with the healing of faces and mouths that had to be rebuilt due to extensive cancer.

Leech saliva contains a powerful mix of over 30 different proteins that numb pain, lessen swelling, and keep blood flowing. Usually, leeches are used one at a time. They fill up with blood and then are replaced as they drop off (about every 20 minutes) for a day or two. Then they are replaced less often for a few more days until they are finally removed altogether.

Like leeches, maggots (fly larvae) were once a common medical therapy used throughout history to treat wounds. Military doctors had long noted that even serious battlefield wounds that were filled with maggots healed quicker, with less infection than maggot-free injuries. After the discovery of infection-zapping penicillin, treating wounds with maggots fell out of medical favor.

But in recent years, scientists have found out how maggots do their healing work -- the growing larvae secrete enzymes that selectively liquefy dead tissues. Then they eat the dead and infected tissue within a wound (a process known as debridement).

In some cases, such as diabetics with deep sores in limbs that are infected with antibiotic-resistant bacteria -- maggots do such a good job of debridement that they can actually save a foot or leg that would otherwise have to be amputated.

As the worm turns

Immune-mediated diseases like inflammatory bowel disease, multiple sclerosis, allergies and asthma are far more prevalent in highly-developed industrialized countries than in poor, third-world countries. And some scientists think it’s because modern hygienic practices prevent people from being exposed to parasitic worms (helminths).

So how could being free of intestinal worms be a bad thing? Epidemiologic studies suggest that people who carry worms are less likely to have an immune-mediated disease. What’s more, several clinical trials have shown that being deliberately infected with certain types of worms reduces disease activity in patients with ulcerative colitis or Crohn's disease.

University of Iowa gastroenterologist Joel Weinstock has been in the forefront of testing this idea. He theorizes that in a disease like inflammatory bowel disease (which causes chronic diarrhea, abdominal pain, weight loss and fever), the immune system is in overdrive. But helminth therapy causes the immune response to calm down, relieving symptoms.

Weinstock studies have included testing worm therapy in 120 patients with Crohn's disease or ulcerative colitis, types of inflammatory bowel disease which affect about a million Americans. The treatment, which involved infecting the research subjects with tiny whipworms, was tolerated well and appeared to improve symptoms.

Fortunately, the worms used for helminth therapy aren’t long snake-like creatures. Instead, they are less than half an inch long, don’t wander outside the intestines, only live about six weeks and don’t appear to make people sick. In fact, by successfully altering the immune response that causes out-of-control inflammation, worm therapy could hold promise in treating other types of autoimmune diseases.

Sherry Baker is a writer from Atlanta, Georgia. She last wrote Jumping Java! for Synergy. Sherry can be reached at featuredstories@adamcorp.com.