Effects of a Psychobiotic Supplement on Serum Brain-derived Neurotrophic Factor Levels in Depressive Patients: A Analysis of a Randomized Clinical Trial.

BACKGROUND/AIMS: Psychobiotics are probiotics or prebiotics that, upon ingestion in adequate amounts, yield positive influence on mental health via microbiota-gut-brain axis regulation to modulate the circulating cytokines, chemokines, neurotransmitters, or neurotrophins levels. We have recently shown that a psychobiotic combination ( R0052 and R0175; CEREBIOME) significantly improved depression symptoms in patients with depression. Recent animal data suggest the influence of the gut microbiota on brain-derived neurotrophic factor (BDNF), which was shown to correlate with antidepressant response in depressive patients. Therefore, we conducted this exploratory analysis of BDNF levels to clarify the mechanism of action of this psychobiotic in our cohort.

METHODS

Our study was a double-blind, randomized controlled trial of patients with low-to-moderate depression receiving either a probiotic combination, prebiotic or placebo. From the 110 patients randomized in the trial, 78 were included in this analysis (probiotic, n = 28; prebiotic and placebo, n = 25). We compared serum BDNF levels from participants at baseline and endpoint, and assessed the Pearson correlation between depression severity and BDNF levels for each intervention.

RESULTS

We found that post-intervention BDNF levels were significantly different between groups ( < 0.001). Furthermore, BDNF levels increased significantly in the probiotic group compared to both the prebiotic ( < 0.001) and placebo groups ( = 0.021), which inversely correlated with depression severity compared to placebo (ANOVA/ANCOVA, = 0.012; Pearson, = -0.79, < 0.001). In the prebiotic group, BDNF levels reduced but not significantly compared with placebo group ( > 0.05).

CONCLUSION

Eight-week supplementation with B. longum and L. helveticus in depressive patients improved depression symptoms, possibly by increasing BDNF levels.