College of Science and Engineering



Faculty Mentor

Carolyn Stenbak, PhD

Faculty Editor

Brett Kaiser, PhD

Student Editor

Lee Sasaki


The hygiene hypothesis describes how human exposure to parasitic helminth worms (and other microorganisms) impacts immune system functions. The potential impacts include protection against autoimmune and allergic disease. Epidemiological disease mapping reveals cases of allergic and autoimmune disease are disproportionately concentrated in urban, developed countries where there is less risk of parasitic infection. This suggests an inverse correlation between autoimmune diseases and likelihood of helminth infection. These observations have led researchers to posit that helminth worms have coevolved alongside their human host. This hypothesis is supported by helminth antagonization of human anti-inflammatory responses. There is some evidence to suggest that helminth worms manipulate an anti-inflammatory cytokine, interleukin-10. This manipulation of IL-10, which is regulated by T helper cells, helps to maintain low levels of inflammation in the gut, and, as a byproduct, reduces risk of autoimmune disease. For this reason, similar modulation of the IL-10 pathway via parasitic induction or drug development could be useful for treating and even preventing certain diseases. This paper will discuss the hygiene hypothesis and its relevance to allergic and autoimmune disease research, emphasizing how helminth worms are currently being used to prevent and treat type 1 diabetes in diabetic mice models. Furthermore, this review provides a table to organize the following: various helminth worms; the worms’ host environments; the autoimmune diseases in which the helminth worm has been found to be immunoregulating; and the specific proteins and immunomodulatory molecules secreted by the species of worm.