Immunobiotics and Immunity Against Parasites

Abstract

Parasitism represents a “win-lose” situation in which one organism benefi ts from the relationship while the other member is harmed by it (Faust and Raes 2012). Actually, parasites could lead from undetectable or minor effects to debilitating or fatal diseases. In addition, it has been demonstrated that interaction with parasites could lead to dramatical modifi cation of the host’s phenotype (Goodman and Johnson 2011). A broad vision of parasites will include in this group both prokaryote and eukaryote organisms but in this chapter the term “parasite” refers to protozoan and metazoan organisms able to provoke disease in vertebrates. Parasites have evolved to exploit the host’s resources in a way that maximizes the likelihood of their continuity on Earth. Successful parasites preserve their host at least until transmission to another individual is accomplished. Should this step is not complete before host death the parasite will be committed to extinction. In this evolutionary frame, life cycles of several parasites reach high degrees of sophistication in order to guaranty permanence. Life cycle of many parasites includes passage or colonization of the digestive tract and the interaction with the host’s microbiota and factors that lead to the modifi cation of the balance between intestinal inhabitants may affect signifi cantly the infection by parasites. A hallmark in parasite life is the ability to respond to changes in the environment by phenotypic changes that allows the organisms to adapt to very variable conditions. This phenotypic plasticity constitutes a successful strategy for survival (Mideo and Reece 2012).