Differences of BDI-II (Beck Depression Inventory-II) score before and after probiotics administration

Background: Depression is related to the dysregulation of neuroendocrine, neuroimmune, metabolic, and neurotransmitter systems. Gut microbiota is suspected to affect these pathway’s dysregulations. Probiotic can improve depression symptoms through the microbiota-gut-brain axis. Aim: To analyze differences in the BDI-II score before and after 28 days of probiotic administration. Methods: This study was quasi-experimental, a single-blind, pre-posttest with the control group. The sample was ninety medical students randomized and divided into two groups, probiotic group (Lactobacillus rhomnosus and Lactobacillus helventicus) (n=50) and placebo group (n=40). A capsule of probiotic or placebo per day was administered for 28 days. The data were gathered using the Beck Depression Inventory-II (BDI-II). Wilcoxon test and Mann Whitney test were used to analyze the data. Results: Mean of BDI-II score before the intervention was 8.29±8.53, while the mean of BDI-II score after probiotic administration was 2.97±4.1. There was a significant difference BDI-II score after the intervention in the probiotic group (5 (0-27) compared to 2 (0-19), p = 0.001). Conclusion: This study proves that probiotic administration could reduce depressive symptoms. Therefore, it is recommended for the mental health professional to administer a probiotic supplement to decrease depression symptoms.