Additional file 1: Fig. S1. The Shannon and Simpson indices. The majority of the rarefaction curves tended to approach the saturation plateau, suggesting that the sequencing depth of the gut microbiome was sufficient for each group. Fig. S2. Extracted ion chromatograms of the 15 neurotransmitter standards. The metabolites were separated by chromatography, and each chromatographic peak was sharp and symmetrical. Table S1. 16S rDNA sequencing results of rats in vehicle control, PTZ + vehicle, and PTZ + Q808 group.