ABSTRACT
Microbiota are essential for the maintenance of health, as they contribute to food digestion and the development and optimal functioning of the immune system (Hooper and Gordon 2001). Interest in the benefi cial functions of microbiota has resulted in the selection of specifi c species with putative health-promoting capacities for the treatment of conditions in which microbiota-or their optimal functioning-have been disrupted. These microorganisms, recognized as probiotics, are generally selected from Lactobacilli or Bifi dobacteria strains (Marco et al. 2006). The probiotic defi nition of Food and Agriculture Organization/World Health Organization retains
the historical elements of the use of living organisms for maintaining good health through the control of microbial balance but also includes direct interaction of microorganisms, their derivatives, and metabolites without the maintenance of microbial balance (Reid 2006). Many animal and clinical studies support a unique role for probiotics by modulating the mucosal immune system. Thus, a new term is required to identify bacteria that promote health by regulating the mucosal immune system. Clancy suggested the term “immunobiotics” as appropriate for fulfi lling this need (Clancy 2003). Moreover, the term “immunogenics” has been proposed to describe immunoregulatory substances and effector molecules present in immunobiotics (Kitazawa et al. 2008).
