Fig. 6

Effects of potential psychobiotics on chronic unpredictable mild stress (CUMS)-induced anxiety-like and depression-like behavior in rats. a Rat treatment and experimental procedure. After 4 weeks of CUMS treatment, normal saline (group CUMS), fluoxetine hydrochlorid (group Flx), B. uniformis (group BU), R. inulinivorans (group RI), and E. rectale (group ER) were inoculated into CUMS-induced depression- and anxiety-like rats. After 4 weeks of continuous inoculation, behavioral tests were performed on rats, including elevated plus-maze test (EPMT), open-field test (OFT), and forced swimming test (FST). After euthanasia (carbon dioxide), brain, feces, and blood samples of rats were collected for analysis. b Behavioral test results of rats in different groups. EPMT and OFT evaluated the anxiety-like behaviors, and depressive-like behaviors were evaluated by FST. c The measurement results of short-chain fatty acids (SCFAs), including propionic acid, butyric acid, isobutyric acid, and isovaleric acid. d The measurement results of neurotransmitters, including gamma–aminobutyric acid (GABA), DL-Kynurenine, 5-hydroxytryptophan (5-HTP), picolinic acid, 5-hydroxyindole-3-acetic acid (5-HIAA), histamine, noradrenaline hydrochloride, and L-glutamine. e The biochemical measurement results, including corticosterone (CORT), diamine oxidase (DAO), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6), intestinal fatty-acid-binding protein (iFABP), lipopolysaccharide (LPS), zonulin, and C-reactive protein (CRP). The values were presented as single data points superimposed to boxplots, and the boxplots were presented with means ± standard error (SE). Differences in the groups were evaluated with one-way ANOVA with Duncan’s test. * P ≤ 0.05, ** P ≤ 0.01, *** P ≤ 0.001