Effect of synbiotic and probiotic supplementation on serum brain-derived neurotrophic factor level, depression and anxiety symptoms in hemodialysis patients: a randomized, double-blinded, clinical trial.

BACKGROUND

The aim of this study was to investigate the effects of probiotic and synbiotic supplementation on the depression and anxiety symptoms and serum brain-derived neurotrophic factor (BDNF) level.

METHODS

Seventy-five HD patients were randomly assigned to receive the synbiotic (15 g of prebiotics, 5 g of probiotic containing T16, BIA-6, BIA-7, and BIA-8 (2.7 × 10 CFU/g each)) or probiotics (5 g probiotics as in synbiotic group with 15 g of maltodextrin as placebo) or placebo (20 g of maltodextrin) for 12 weeks. Serum BDNF was measured by ELISA kit. Hospital Anxiety and Depression Scale (HADS) was used to assess symptoms of depression (HADS-DEP) and anxiety (HADS-ANX).

RESULTS

From baseline to 12 weeks, synbiotic supplementation resulted in a significant decrease in HADS-DEP score in a subgroup of patients with depressive symptom (HADS-DEP ≥ 8) compared to the placebo and probiotic supplementation ( = .001,  = .002, respectively) and in all patients compared to the placebo ( = .004). There was no significant difference among the groups in terms of HADS-ANX scores. However, the HADS-ANX scores decreased significantly in the synbiotic group compared to the baseline in all patients ( = .047) and also patients with depressive symptom ( = .03). In addition, in a subgroup of HD patients with depressive symptom, the serum BDNF increased significantly in the synbiotic group when compared to the placebo ( < .001) and probiotic group ( = .011).

CONCLUSION

Overall, 12 weeks of synbiotic supplementation resulted in greater improvement in depression symptoms and serum BDNF level compared to the probiotic supplementation in HD patients especially in the subgroup of patients with depression symptoms.