Psychobiotics – Probiotics that Improve Mood

Abstract

The human intestinal microbiome includes all microorganisms inhabiting the intestinal tract. One study showed that mice raised in a sterile environment exhibited excessive physiological responses to stress compared to normal control. This discovery revealed the involvement of the microbiome in the development of «The Вrain – Gut – Microbiota Axis». Since then, it has been revealed that intestinal bacteria are involved in the regulation of diverse and important physiological processes, including immunomodulation, obesity and energy balance, as well as the activity of the nervous system. All these studies allowed to identify a new type of probiotics - psychobiotics. Psychobiotics are capable to provide positive impact on patients′ mood. Attempts to reveal intrinsic mechanisms of positive emotional shifts of humans are of a great interest. Ability of psychobiotics to influence the depth of emotions is confirmed. The main neurotransmitter that has an inhibitory effect in the brain of humans and animals is γ-aminobutyric acid (GABA). It is involved in metabolic and neurotransmitter processes in the brain. The precursor of GABA is glutamate. GABA-ergic system of the brain in its structure resembles all the others - a number of deep-seated structures in the brain, from which the nerve fibers that secrete GABA go to other parts of the nervous system. Therefore, GABA is an inhibitory neurotransmitter that regulates many processes - from muscle tone to emotional reactions. Many studies have shown that some types of microorganisms are able to produce GABA, which acts on the human body in the same way as GABA produced in the human brain. The main producers of GABA, as studies have found, are lactic acid bacteria, and among them the most capable bacteria of the genus Lactobacillus helveticus.  According to WHO standards, new strains of probiotics should be clearly identified for further use as dietary supplements or drugs. They must be able to survive in the gastrointestinal tract (be resistant to pH, enzymes, cholic acids, etc.), they must also be capable of adhesion, exhibit antagonistic properties and be genetically stable. Therefore, all strains that can be used in the production of probiotics must be clearly identified at the species level and have a genetic passport. The work of identifying and introducing new strains of probiotics capable to produce psychobiotic substances, namely GABA, is very painstaking, but at the same time very important because stress, depression and many other types of mental disorders are becoming more common in the world and the Ukraine is no exception