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.