The Cancer Hygiene Hypothesis: From Theory to Therapeutic Helminths

Abstract

Background:: The “Hygiene Hypothesis” was postulated by David Strachan in 1989 to explain for the rapid 20th century increase in allergic diseases such as asthma. In this hypothesis, children from developed countries living in ultra-hygienic environments and avoiding exposure to viruses, bacteria, and parasites, especially helminthes, have an increased risk of atopic disorders. Materials & Methods:: Research and online content related to cancer hygiene hypothesis is highlighted and to illustrate key themes. Guidelines for meaningful participation in DOC activities for people with diabetes, families, health care providers, and industry are provided. Results:: The lack of worms leads to failure of stimulation of mucosal Th2 responses. These infections exert their effect through critically altering T-helper (Th)1/Th2 regulation, and it is postulated that, thus, they protect against atopy and asthma, through the induction of Th1 regulatory response. It is now also recognized that this “hygiene hypothesis” concept applies to a wider range of chronic inflammatory diseases than atopy and asthma, such as diabetes, multiple sclerosis and cancer. Conclusion:: Here we discuss the major implications of these findings for the association between microorganisms and cancer, and also between some immune pathologies, like autoimmune diseases, and cancer.

Editorial: Parasites and Cancer

“…Corroborating these results, Ferreira et al (1) showed that Fasciola hepatica extracts induced death of Chine Hamster Ovary (CHO) cells suggesting that some molecules contained in F. hepatica extracts could have a potential as a preventive or even curative anti-cancer substance. These data sustain the defensive shield of infections, as anticipated by the cancer hygiene hypothesis (2).…”

Risks of oncologic pathology in parasitosis at the present time

“…S. Ferreira и соавт. [49] показали, что экстракты Fasciola hepatica вызывают гибель клеток рака яичника китайского хомячка, что позволяет авторам предположить наличие некоторых молекул в F. hepatica, которые могут иметь профилактическое или даже лечебное противораковое действие [50].…”

Cancer hygiene hypothesis: A test from wild captive mammals

“…This includes, among others, the suppression of inflammation, the promotion of antitumour immunity or the alteration of the tumour microenvironment, preventing cancer progression (see Oikonomopoulou et al, 2013). Helminths, for example, are relatively well documented in mammals and look particularly promising considering their positive effect on autoimmune diseases in humans (Fernandes et al, 2019; Greb & Gottlieb, 2013; Stephens et al, 2017; Summers et al, 2003, 2005). Under this hypothesis, we predict that animals with high parasite diversity in the wild, either overall or disaggregated by major parasite groups, should experience the greatest parasite mismatch when in the zoo, which should, all else being equal, exacerbate their cancer risk.…”

“…The fact that symptoms of Crohn's disease can be ameliorated by ingesting eggs of a porcine nematode (e.g. Trichuris suis , which hatches but does not grow in humans, see, Summers et al, 2005) opens up prospects for possible applications of evolutionary medicine in the treatment of some modern health disorders (Fernandes et al, 2019; Greb & Gottlieb, 2013; Summers et al, 2003).…”