Study On Relationship Between Gut Microbiota And Depressive Disorder

[Objective]FH/Wjd depression rats and normal SD rats were used as the research object, comparing the changes of their gut microbiota with age, as well as the change of serum metabolic spectrum, to explore the relationship between gut microbiota and depression, and finally provide the basis for clinical trials study of intestinal microbial colony structure patients with depression.[Methods]1. Forced swimming test (FST) and sucrose preference test (SPT) were used to validate the depressive trait of FH/Wjd rats.2. Fecal bacterial diversity in depression rats and normal rats was profiled by454pyrosequencing of the V3region of16S rRNA gene and multivariate statistics, in order to study the differences of gut microbiota between depression rats and normal rats, and analyze the dynamic change of depression rats’gut microbiota with age.3. Using serum metabolomics research methods based on gas chromatography mass spectrometry (GC-MS) technology to analyze the differences of metabolite profiles between depression rats and normal rats, as well as the dynamic change of depression rats’serum metabolites with age.[Results]1. Validation of depressive trait of FH/Wjd rats(1) SPT:The ratio of sucrose to total liquid consumed by FH/Wjd rats (n=16) at6,7and8weeks of age were86.79%±6.78%,72.11%±11.80%and77.88%≈±6.92%respectively, and the ratio of sucrose to total liquid consumed by FH/Wjd rats (n=16) at6,7and8weeks of age were75.24%±6.37%,65.58%±12.09%,61.59% ±17.81%. It’s indicated that the ratio of sucrose to total liquid consumed by FH/Wjd rats were significantly lower than those of SD rats at6,7and8weeks of age, and p value is less than0.001,0.047and0.002respectively.(2) FST:The immobility time of FH/Wjd (n=16) rats at6,7and8weeks of age were78s±48s,60s±29s and73s±29s respectively, the immobility time of SD (n=16) rats at6,7and8weeks of age were132s±32s,121s±59s,133s±49s respectively. The results showed that the immobility time of FH/Wjd rats were significantly longer than that in SD rats at6,7and8weeks of age, and p value is0.001,0.003and less than0.001respectively.2. Analysis of structure of gut microbiota(1) There were significant differences in gut microbiota between depression rats and normal rats, thirteen genera was significantly lower in depression rats, such as Bacteroides, Lachnospira, Coprococcus, Ruminococcus, etc. Five genera was significantly more abundant in the gut microbiota of depression rats, such as Rikenella, Oscillibacter, Anaeroplasma, etc.(2) The dynamic change of depression rats’gut microbiota with age showed microbiota changes of eight genera, such as Acinetobacter, Oscillibacter, Bacillus, Bilophila, etc.3. Analysis of serum metabolic spectrum(1) There were significant differences in serum metabolic spectrum between depression rats and normal rats, mainly about the process of the metabolism of amino acids, glucose metabolism and lipid metabolism and other metabolic pathways, especially in amino acid metabolism, like L-Threonine, Serine,5-Hydroxytryptamine, Proline, beta Alanine, Glutamic acid, L-Asparagine,3-Hydroxybutyric acid and other metabolic substances.(2) The dynamic change of depression rats’serum metabolic spectrum with age had significant differences, mainly involving amino acid metabolism, sugar metabolism and lipid metabolism and other metabolic pathways. In terms of amino acid metabolism, metabolic substances, including Citrulline, L-glutamine, Urea, Creatinine, Glutamic acid,3-Hydroxybutyric acid, L-threonine,etc, changed with the age.[Conclusions] 1. Forced swimming test (FST) and sucrose preference test (SPT) had verified the depressive trait of FH/Wjd rats, FH/Wjd congenital depression rats can be used as an experimental model for studying depression disease.2. The gut microbiota of FH/Wjd depression rats and normal SD rats had significant differences,and the gut microbiota of depression rats changed with age dynamically.3. The serum metabolic spectrum of FH/Wjd depression rats and normal SD rats had significant differences, and the serum metabolites of depression rats changed with age dynamically.