Chaihu-Shugan-San, a traditional Chinese medicine, positively impacts gut microbiota in mice, thus reducing stress-induced anxiety and depression symptoms.
In the methodology, Chaihu-Shugan-San was extracted with boiling water and freeze-dried. Anxiety and depression were induced in C57BL/6 mice through restrain stress. Measurements for anxiety and depression-related behaviours were taken using the light/dark transition and elevated plus maze tasks, the forced swimming test, and the tail suspension test. Enzyme-linked immunosorbent assay and immunoblotting were used to assay biomarkers. The composition of gut microbiota was established using the Illumina iSeq sequencer.
In the results, Chaihu-Shugan-San significantly reduced anxiety and depression-like behaviours in the mice, suppressing stress-induced gut inflammation and overactive stress reactions while increasing suppressed brain-derived neurotrophic factor expression. Additionally, it altered gut microbiota composition, reducing specific bacteria populations while increasing others that had been suppressed by stress. It was seen that the fecal transplantation from control or Chaihu-Shugan-San treated mice into stress-exposed mice significantly improved their anxiety and depression-like behaviours.
