Probiotic agents have received growing attention in recent years as an alternative therapeutic tool in the management of irritable bowel syndrome. In this article, we will discuss the rationale that support this indication, including the role of intestinal microbiota in gastrointestinal function in both human and animal models, potential links between an impaired microbiota imbalance and the psycho-immunopathophysiology of irritable bowel syndrome, and the results of the available clinical trials to date.