ABSTRACT
Eli Metchnikoff received the Nobel Prize for observations on the value of lactic-acid-producing bacteria in enhancing health and longevity [1,2]. Since the time of Metchnikoff, scientists have been exploring the role of the gut microŽora in the prevention and mitigation of illness. Presently, there is abundant data to support the notion that administration of certain strains of gut microbiota can become either useful adjuncts or even primary therapy for a number of gastrointestinal and systemic conditions. This microbial ecosystem has the ability to function as a “virtual” organ system that aids host nutrition and maintenance of homeostasis. This chapter reviews the clinical trials of probiotics for intestinal and systemic disorders while highlighting the potential mechanisms of action. The potential mechanisms of action of probiotics are shown in Figure 3.1.
