Effect of prebiotic and probiotic supplementation on circulating pro-inflammatory cytokines and urinary cortisol levels in patients with major depressive disorder: A double-blind, placebo-controlled randomized clinical trial

Abstract

The aim of this double blind, placebo-control trial, was to investigate the effect of prebiotic and probiotic on serum inflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-10), Beck Depression Inventory (BDI) score and urinary cortisol in patients with major depressive disorder (MDD). Randomized participants (n = 110) received either the probiotic, prebiotic or placebo for 8 weeks. Eighty-one subjects completed the trial. The BDI score decreased significantly in the probiotic-treated vs control group. For all cytokines, levels were similar between groups. Cortisol levels decreased by 20% and 19% of baseline in the probiotic and prebiotic groups, respectively, and remained unchanged in the placebo group. Overall, although probiotics improved depression symptoms, serum inflammatory marker levels were not. Prebiotics had no effect on depression symptoms nor inflammatory marker levels. While changes in urinary cortisol levels were not statistically significant among groups, the decreases in the probiotic and prebiotic groups are considered clinically significant.

Keywords

• Probiotic
• Prebiotic
• Depression
• MDD
• Cortisol
• Inflammatory markers