Technology Review reports mounting evidence in both humans and animals suggests that infection with these parasitic worms seems to protect against a number of inflammatory diseases, including asthma and allergy, multiple sclerosis, Crohn’s disease, and type 1 diabetes
We became dependent on helminths [parasitic worms] and made ourselves vulnerable to immunologic diseases. A number of epidemiological studies have shown that people infected with parasitic worms suffer less from allergies and other immune diseases, and research in animal models designed to mimic these diseases supports these findings. The rise in allergies and other ailments in rich countries over the last few decades has been matched by a decrease in parasitic worm infection, among other factors. Researchers found that people with parasitic infections have these unique protein fragments in their bloodstreams, while unaffected people have few or none.
Scientists hope to decipher how these organisms control the immune systems of their human hosts and to develop new therapies that replicate the parasites’ beneficial effect. “We can treat people with worms, or can we figure out how worms protect, and discover a new way to treat allergies by mimicking what worms do,” says Ed Mitre, a physician and scientist at the Uniformed Services University in Bethesda, MD. “My general feeling is that we should be trying to induce the types of immune responses we see in chronic worm infections.”
New technologies that allow scientists to analyze microbes more precisely than ever before will reveal why allergy rates in Sweden and other wealthy nations, including the United States, have risen dramatically over the past 50 years, while rates in historically poorer nations, such as Estonia, have not.
Findings could provide a new twist on the hygiene hypothesis, which suggests that rising allergy rates are linked to our more antiseptic, modern lifestyle. If scientists can find the elusive x factor that either protects against allergies or increases risk for them, they may be able to recreate it, perhaps by dosing mothers or babies with healthy bacteria, known as probiotics. “We’re on the verge of a revolution in understanding the human microbiome,” says Björkstén. “The key to understanding these diseases may be in the gut, rather than in the environment.”
Initial studies of the children’s gut microbes using traditional microbiology approaches have yielded tantalizing clues into their role in allergy: the number and diversity of microbes inhabiting a baby’s gut soon after birth seem to predict his likelihood of later developing allergic disease. In addition, babies born in urban environments have fewer microbes and fewer diverse microbial communities than those born and raised on farms.