Psychobiotics: A new perspective on the treatment of stress, anxiety, and depression

Psychobiotics are a new class of psychotropics that include living microorganisms and substances that exert a beneficial effect on patients with psychopathologies. Psychological disorders affect millions of people around the world, being the most common those that involve suffering from stress, anxiety and depression. Traditionally, these disorders have been treated through a wide range of therapies, both psychological and pharmacological. It has recently been shown that dysfunction of the gut-brain axis may be involved in these psychological disorders, and that the restoration of the altered microbial ecosystem could constitute a useful instrument for the prevention and treatment of various psychopathologies. The objective of the present work is to carry out a narrative review on the interventions that use different psychobiotics (probiotics, prebiotics, synbiotics, postbiotics, and paraprobiotics) to improve various psychological disorders in humans, mainly related to stress, anxiety and depression. Likewise, various future perspectives of its application in therapeutic interventions for the aforementioned disorders are proposed.