PSYCHOBIOTICS - PROBIOTICS THAT ELEVATE MOOD

The human intestinal microbiome includes all microorganisms inhabiting the intestinal tract. One of studies showed that mice raised in a sterile environment exhibited excessive physiological responses to stress, as compared with the normal reference animals. This discovery revealed the involvement of the microbiome in the development of the brain - gut - microbiota axis. Since then, it has been found that intestinal bacteria are involved in regulating diverse and important physiological processes, including immunomodulation, obesity, energy balance, and the function of the nervous system. All these studies have allowed identifying a new type of probiotics - psychobiotics. Psychobiotics can produce a positive effect on a patient's mood. Attempts to reveal the internal mechanisms of positive emotion shifts in people are of a great interest. It has been confirmed that psychobiotics can influence the depth of emotions. The main neurotransmitter that acts as an inhibitor in the brain of humans and animals is y-aminobutyric acid (GABA). It is involved in metabolic and neurotransmitting processes in the brain. The precursor of GABA is glutamate. The GABA-ergic system of the brain structurally resembles all the others: a number of deep-lying structures in the brain, from which the nerve fibres that secrete GABA run to other parts of the nervous system. Thus, GABA is an inhibitory neurotransmitter that regulates many processes, from muscle tone to emotional reactions. Many studies have shown that some microorganisms can produce GABA that acts on the human body in the same way as GABA produced in the human brain does. The main producers of GABA, according to the studies, are lactic acid bacteria, and among them, the most capable are those of the genus Lactobacillus helveticus. According to the WHO standards, new strains of probiotics should be clearly identified to be further used 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. So, all strains supposed to be used in the production of probiotics must be clearly identified at the species level and have a genetic passport. Identifying and introducing new probiotic strains able to produce psychobiotic substances (GABA) is a painstaking task. It is a very important one, though, because stress, depression, and many other mental disorders are becoming more common in the world, and Ukraine is no exception.