Essentially, helminth symbionts modulate the human immune system in subtle yet complex ways, ‘regulating’ or ‘balancing’ overactive immune responses associated with allergic, inflammatory and autoimmune disorders.
“Recent studies have indicated that infectious agents stimulate a large variety of regulatory T cells, such as Th2, Treg, Tr1, and NKT cells, which secrete immunosuppressive cytokines/chemokines, such as IL-10 and TGF-β to alter the Th1/Th2 balance. Additionally, the innate immune system is also associated with the hygiene hypothesis. Infections may induce the generation of regulatory macrophages, dendritic cells, innate lymphoid cells (ILC), NK, and B cells. TLR-MyD88 pathway is believed to be involved in the induction of different subsets of regulatory T cells, such as Treg and NKT cells. The ability of infectious agents to regulate the immune system of their host is an increasingly fascinating topic.”
Effects of Invariant NKT Cells on Parasite Infections and Hygiene Hypothesis by Jun-Qi Yang, Yonghua Zhou, and Ram Raj Singh