Anyone who has ever seen Divine in Pink Flamingos will know that eating dog poop is not pretty, but in fact, according to Jane Brody in the New York Times, it may be an instinctive behavior that has helped us survive as as a species.
And while we at TreeHugger have railed against the use of antibiotic hand cleaners with Triclosan, researchers of the "hygiene hypothesis" go further than that- they suggest that dirt is good for you, both on your hands and in your gut.
One leading researcher, Dr. Joel V. Weinstock, the director of gastroenterology and hepatology at Tufts Medical Center in Boston, said in an interview that the immune system at birth "is like an unprogrammed computer. It needs instruction."
"Children raised in an ultraclean environment," he added, "are not being exposed to organisms that help them develop appropriate immune regulatory circuits."
Others go even further and suggest that the reason babies go after excrement is for that historically important event, the Diet of Worms.
Studies he has conducted with Dr. David Elliott, a gastroenterologist and immunologist at the University of Iowa, indicate that intestinal worms, which have been all but eliminated in developed countries, are "likely to be the biggest player" in regulating the immune system to respond appropriately, Dr. Elliott said in an interview. He added that bacterial and viral infections seem to influence the immune system in the same way, but not as forcefully.
Weinstock suggests that
"A lot of inflammatory diseases — multiple sclerosis, Crohn's disease, ulcerative colitis and asthma — are due to the activity of Th 17," he explained. "If you infect mice with worms, Th 17 drops dramatically, and the activity of regulatory T cells is augmented."
So let your kids go barefoot, don't make them wash their hands every five minutes, don't waste so much time cleaning house, get a dog and a cat. Everyone will evidently be healthier and happier.