Do microbes affect human health?

Recent research has revealed that some intestinal helminths may provide our bodies with unexpected beneficial functions. Kateřina Jirků-Pomajbíková and Julius Lukeš of the Czech Academy of Sciences’ Biology Centre’s Institute of Parasitology provide details in an article in this issue. Indeed, over the past decade, the rapid increase in allergies in industrialized countries, chronic inflammatory diseases and various immune-mediated disorders have been reduced by efficiently eliminating helminth infections. Current circumstantial evidence suggests that humans infected with helminths are likely to have a lower incidence of immunological disorders, cardiovascular diseases and even lower cholesterol. At times, some parasites are finely tuned to a given host, causing minimal if any, pathogenicity. In fact, their inherent immunogenicity may have a positive effect, due to manipulating the immune response of the host. Generally speaking, the so-called “Old Friends Hypothesis” postulates that contact with any kind of antigen stimulates the proper development of the immune system, whereas low exposure to antigens predisposes an individual towards hyperactive and otherwise inappropriate immune responses. Hence, helminth parasites may have important protective effects against immunological disorders during early immune maturation.