Ecology of probiotics and enteric protection

Abstract

Insight into the diversity and function of the human gut microbiota has been gained through recent studies with probiotic bacteria that exhibit specific functions positively affecting our health, such as immunomodulation. Initial efforts have been centered on establishing scientific support for the efficacy of some probiotic bacteria, mainly Lactobacillus and Bifidobacterium species, for prevention of enteric infection. Following these evidence-based functional approaches, considerable research is focused on elucidation of mechanisms of action of particular probiotic bacteria. Different probiotic strains vary in their ability to protect the host from enteric pathogen interactions and, the efficient dose, frequency and duration of the probiotic consumption required in different population groups remain to be determined. The taxonomy of probiotics, in relation to their functional physiology and their potential for enteric protection will be discussed in this chapter. A special focus is placed on recent in vitro and in vivo assessments of particular probiotics for inhibition of enteric pathogens using gut fermentation models, cellular tests, animal and human trials. Finally, mechanisms that contribute to the inhibition of pathogens in the gut environment will be addressed through intestinal epithelial cell models. © 2011 Springer Science+Business Media B.V.