Scientific Report for Parmalat: Survey of Known Probiotics [Species / Strains] and Prebiotics with a Potential Health Benefit and Immunogenic Effects

The intestinal microbiota plays a fundamental role in maintaining immune homeostasis. There is ample evidence from in vitro, in vivo laboratory animal studies linking probiotic bacteria activity to healthy outcomes. Subsequent human clinical trials investigating the influence of various probiotic organisms, either alone or in combination, on immune parameters, infectious outcomes, and inflammatory conditions have conclusively demonstrated that probiotic species such as Lactobacilli display stimulatory properties on cells of the innate immune system. As a consequence, dairy products fermented with lactic acid bacteria for example such as yoghurt, are popular carriers of probiotics and in certain instances combined with prebiotics, to influence the innate immune system. The overall conclusions from this focused effort has seen significant effects reported to some components of the immune response, including phagocytosis, natural killer (NK) cell activity and mucosal immunoglobulin A production [especially as seen in children], that have been attributed to specific preparations containing probiotic bacteria. Other components, including lymphocyte proliferation, the production of cytokines and of antibodies other than immunoglobulin A appear less sensitive to probiotics although not out of the realm of plausible biological influences as evidenced by specific in vitro studies [see Appendix IV]. The activites elicited by probiotic strains have direct and indirect immunogenicity potential effects for the human host.