Synbiotic diet produces antidepressant-like effects but alters ketamine activity in an avian model of treatment-resistant depression.

Pre- and probiotics promote a diverse and functional gut microbiota and have demonstrated both anxiolytic and antidepressant effects; however, how synbiotic diet interacts with antidepressant medications has not been fully investigated. This study sought to evaluate the potential anxiolytic or antidepressant effects of a synbiotic diet in an avian model that presents homologies with treatment-resistant depression. In addition, we sought to evaluate the potential interaction of a synbiotic diet combined with select doses of ketamine.