Several studies have investigated how the use of probiotic supplements containing Bifidobacteria and Lactobacilli affect the clinical outcome of patients with IBS. However, to date, no studies have assessed whether fermented vegetables, a "natural" source of probiotic bacteria, are useful in the treatment of IBS. Moreover, little is known about how other types of probiotic bacteria, such as those belonging to the genus Escherichia, affect symptoms of IBS.