Chronic unpredicted mild stress(CUMS) combined with isolated feeding was used to induce depressed rat model. The anti-depressant effects of Zhizichi Decoction(ZZCD) and its solid fermented product(ZZC) were analyzed by behavioral test and comparison of pathological tissues of hippocampus and liver, metabolic characteristics of intestinal flora, and relative abundance of species. The results showed that ZZC could increase sucrose preference, shorten the immobility time in the forced swim test and tail suspension test(P<0.05), and repair damaged hippocampus and liver tissues, and the effect was superior to that of ZZCD. The results of Biolog ECO plates showed that the average well color development(AWCD) of intestinal flora in the model group significantly decreased and the metabolic levels of sugar and amino acids were reduced, while the AWCD of the treatment groups increased. The metabolic levels of the two carbon sources were improved in the ZZC group, while only sugar metabolic level was elevated in the ZZCD group. Metagenomic analysis of intestinal flora showed that the ratio of Firmicutes/Bacteroidetes was 3.87 in the control group, 21.77 in the model group, 5.91 in the ZZC group, and 18.48 in the ZZCD group. Lactobacillus increased by 3.28 times, and Prevotella and Bacteroidetes decreased by 75.59% and 76.39%, respectively in the model group as compared with that in the control group. Lactobacillus decreased by 31.13%, and Prevotella and Bacteroidetes increased by more than three times in the ZZC group as compared with that in the model group, while the corresponding changes in the ZZCD group were not significant. ZZC could improve depression-like beha-viors by regulating the structure of intestinal flora and metabolic functions and repairing damaged hippocampus and liver tissues in depressed rats, showing an anti-depressant effect superior to that of ZZCD. This study is expected to provide a basis for the development of new anti-depressant food products.
Keywords: Biolog-ECO; Zhizichi Decoction; depression; hippocampus; intestinal flora; liver; metagenome; solid fermentation.