Adjunct therapy with probiotics for depressive episodes of bipolar disorder type Ⅰ: A randomized placebo-controlled trial

Background: Probiotics adjuvant therapy might enhance the efficacy of the conventional medications of bipolar disorder type Ⅰ (BD-Ⅰ). Methods: A randomized double-blind placebo-controlled design was implemented in this study. We randomly assigned 98 patients with depressive BD-Ⅰ to receive the combined treatment of probiotics (Bifidobacterium animals subsp. lactis BAMA-B06/BAu-B0111, 2 g/day) (N = 49) and conventional medications, or conventional medications along with placebo (maltodextrin, 2 g/day) (N = 49). Primary endpoints were the change from baseline to 30 days in the scores of 17-item Hamilton Depression Rating Scale. Results: Compared with control group, HAMD-14 scores were further decreased significantly and the increase trend of fasting blood glucose were suppressed in treatment group. Subsequent correlation analysis revealed there were close associations between the relative abundance of Firmicutes, serum levels of fasting blood glucose and HAMD-14 scores. Conclusions: Probiotics adjuvant therapy can enhance the efficacy of the conventional medications of depressive BD-Ⅰ and reduce the metabolic side effects.