Hygiene Hypothesis and Autoimmune Diseases
As reported by David Gutierrez in , researchers in a study conducted at the University of Nottingham point out that humans and gastrointestinal parasites might have coevolved in a way that the parasites actually help regulate the human immune system to prevent allergies.16 They believe that over the course of millions of years, gastrointestinal parasites have evolved the ability to suppress the human immune system as a survival mechanism. Because parasitic infestation has been so common throughout human evolutionary history, the human immune system has in turn evolved to compensate for this effect. This means that if the parasites are removed, the immune system may actually function too strongly, resulting in maladaptive immune responses such as asthma, allergies, and eczema. To test this concept the researchers studied over 1500 children in rural villages in Vietnam where parasitic infestation with hookworm is extremely common and allergies are not. Eradication of parasitic infection resulted in skyrocketing incidence of allergy, including dust mite sensitivity, supporting the hypothesis that parasites were modeling their immune response.
With issues such as the hygiene hypothesis, and the role of parasites in immune function in mind, gastroenterologist and researcher Dr. Joel Weinstock, originally at the University of Iowa and now Tufts University, has performed novel work with subjects with inflammatory bowel disease (IBD).17 IBD was unheard of before the 20th century. Beginning of 20th-century incidence is thought to be about 1:10,000 and is now 1:250. Similar data exist with the incidences of asthma, hay fever, DM, MS, and so on. Weinstock conducted various studies of IBD patients and treated them with the therapeutic parasite Trichuris suis, a porcine whipworm, which was an ideal choice as it only remains viable in the human GI tract for a short time and must be continually administered. The organism, when introduced into patients with IBD induced changes in regulatory T cell function, blocked T cell proliferation, altered cytokine production and expression of innate immunity, altered the intestinal flora, and generally produced a lessening of symptoms and severity of disease. Pharmaceutical agents are now being developed along these lines to treat IBD.
The 'Hygiene Hypothesis' for Autoimmune and Allergic Diseases: ..
Hygiene Hypothesis and Autoimmune Diseases - …
Over the past few decades, the healthcare community has observed an intriguing phenomenon: diseases related to the immune system - type 1 diabetes, and other autoimmune diseases, allergies, and the like - have taken hold in countries that have thriving, modern economies, while barely making a mark in the developing world. One of the best-supported theories to explain this peculiar public health pattern has been dubbed the hygiene hypothesis. The theory is based on the premise that exposure to pathogens early in life is actually beneficial to the education and development of the human immune system.
Immune Diseases and the Hygiene Hypothesis - Home …
Looking for Answers
Despite its prevalence, the level of basic autoimmune research funding is below 3% of the National Institutes of Health (NIH) total budget, which may explain why we understand so little about the roots of these diseases. Indeed, AARDA reports that the whole arena of autoimmune research is in its infancy. Though there are many theories about the origins of autoimmune diseases—such as the hygiene hypothesis theory, which suggests that the rise of such diseases in industrialized nations may be linked to cleanliness, vaccines, and decreased exposure to bacteria—scientists don’t fully understand why the immune system is unable to recognize its own cells or regulate its response; thus there are no sure cures or prevention strategies as of yet. We do know there are factors at the root of autoimmune disease development, which include both genetic and environmental components.