Chronic fatigue syndrome (CFS) is the term that is generally accepted by clinicians to encompass the range of complaints that is also referred to as myalgic encephalomyelitis (ME) or chronic fatigue and immune dysfunction syndrome. Given the multitude of symptoms that CFS/ME patients present with, treatment approaches have been broad including immunologic, pharmacologic, behavioral treatment and complementary and alternative medicines CFS/ME is a debilitating multisystem condition characterized by chronic and disabling fatigue. Gut microbial community equilibrium can also be altered by psychological stress, which has been found to decrease the numbers of Bifidobacteria and Lactobacillus. Probiotics are defined as live organisms that, when administered in adequate amounts conferred beneficial effects on the host. A prerequisite for therapeutic probiotic administration is based on the concept that the gut ecosystem contributes to human physiology, and the gut has an unequivocal connection to the brain and consequently its modulation by use of probiotics, may help maintain health and reduce the risk of disease.