While there is a clear genetic predisposition for some individuals to develop autoimmune disorders, there are also significant environmental interactions, with a near epidemic rise in autoimmune disorders and food allergies in the industrialized world occurring in less than fifty years. Access to clean water, safe food, sanitation, and modern medical care in the last century has led to a near elimination of parasitic infections in modern cultures. Unfortunately, improved sanitation has also been closely associated with an increase in hypersensitivity and autoimmune disorders such as Multiple Sclerosis, Crohn’s, and peanut allergies. It should be noted that tropical and subtropical parts of the world with poor sanitation have high numbers of people with ongoing parasitic infection and extremely low incidences of inflammatory diseases. Additionally when immigrants relocate to the western world with its pristine sanitation, the next generation develops autoimmune disorders and food allergies similar to the industrialized world.
The “hygiene hypothesis,” suggests that parasitic worms fine tune the human immune systems and protect against allergies and autoimmune diseases. Parasites have co-evolved to manipulate their environments so they can live and reproduce without causing the illness or death of their host. By mediating the immune system’s attack against them, parasites can live and reproduce comfortably. Parasites release substances that interact with the host’s chemistry, and the human immune system has slowly adapted to the presence of certain intestinal parasites. By removing the worms and the inhibitory effect that they have on inflammation, the human body can overproduce inflammatory agents, resulting in autoimmune disease.
Autoimmune reactions occur when the immune system launches an attack at something that is not harmful, either a substance in the environment or the individual’s own tissues. Exposure to certain organisms in our natural environment teaches the human immune system which things it needs to respond to and which things it can safely ignore. Exposure to helminthic parasites triggers the fine-tuning of the immune system and teaches it to tolerate the parasite, as well as some overlapping antigens seen in Multiple Sclerosis, Crohn’s and peanut allergies. If the immune system is never exposed to helminths and other fecal microorganisms, it doesn’t mature properly and resulting in an exaggerated response, and development of allergies and autoimmune diseases.
Other autoimmune mediated diseases that may be reduced by parasitic infections include Alzheimer’s disease, asthma, atherosclerosis, some cancers, eczema, hay fever, Parkinson’s disease, type one diabetes, celiac disease, rheumatoid arthritis, and ulcerative colitis.
The use of helminthic therapy with hookworm and TSO is being currently investigated. Data suggests that Multiple Sclerosis, Crohn’s and severe peanut allergies all benefit from induced parasitic infections.