Relevance of immune response against resident and not resident commensal strains for the definition of strategies of probiotic supply in the diet of weaning pigs

Copious research data from trials in vitro and on experimental animals are available showing that the gut immune system could be down- or up- regulated in order to improve the overall health of the host. In some cases it is claimed that humoral immunity was increased, with special emphasis on the stimulation of specific response against certain pathogens. However the development of specific immune response towards commensal bacteria and probiotics is less documented.