Main idea: Complex treatment of selective serotonin reuptake inhibitor with probiotic bacteria LP299v improved cognitive performance and decreased inflammatory markers concentration in mood disorder patients. Decreased kynurenine concentration could contribute to the improvement of cognitive functions in the LP299v group compared to the placebo group. To our knowledge results of this study are the first evidence of improvement of cognitive functions in MDD patients due to probiotic bacteria and this is the first evidence of decreased kynurenine concentration in MDD patients due to probiotic bacteria.
Background: Interactions between the digestive system and the brain functions have become in recent years an important field of psychiatric research. These multidirectional interactions take place in the so-called microbiota-gut-brain axis and emerging scientific data indicate the significant role of microbiota in the modulation of the central nervous system (CNS) including affective and cognitive functions.
Objective: An assessment of psychobiotic and immunomodulatory effects of probiotic bacteria LP299v by measuring affective, cognitive functions, and biochemical parameters in patients with MDD undergoing treatment with special drugs (selective serotonin reuptake inhibitors (SSRI)).
Design: Seventy-nine patients with mood disorders were randomized and allocated to a double-blind, placebo-controlled trial. Participants received either an SSRI with the probiotic LP299v for a period of 8 weeks or an SSRI with the placebo of the probiotic for the same period.
Sixty participants finished the study and were analyzed: 30 participants in the LP299v group and 30 participants in the placebo group. There was an improvement in symptoms for patients with the LP299v group compared with the placebo between baseline and after 8 weeks of intervention. There was a significant increase in kynurenine markers in the LP299v group compared with the placebo group. There were no significant changes in TNF-α, IL-6, and IL-1b and cortisol concentrations in neither probiotic nor placebo groups.