Depression is a common mental disorder, which can be long-lasting or recurrent, substantially impairing an individual's ability to function in their daily life. The first antidepressants were discovered by accident and were being used as an antitubercular agent, but were found to induce euphoric effects in patients with tuberculosis. The World Health Organization affirmed that probiotics, as a live microorganism, when taken in prescribed quantities may lead to beneficial health effects of the host. Gamma-Aminobutyric acid can be produced by intestinal bacteria, and probiotics can modify depressive behavior from y-aminobutyric acid signaling, at least in the rat model. Studies appear to provide evidence which suggest a regulating role for probiotics in relation to the immune response, neuroendocrine, and neurochemical response outside the gastrointestinal tract. Psychobiotics is an approach that combines two avenues, namely probiotics and psychiatric illness. The probiotic products may contain a single microorganism or mixture of several species.