16S rRNA gene sequencing reveals the effect of fluoxetine on gut microbiota in chronic unpredictable stress-induced depressive-like rats

Objectives Gut microbiota is relevant to the pathogenesis of mental disorders including depression. This study aimed to investigate the influence of fluoxetine (FLX) on the gut microbiota in rats with Chronic Unpredictable Mild Stresses (CUMS)-induced depression. Results We confirmed that the 28-day CUMS-induced depression rat model. Chronic FLX administration weakly improved depressive-like behaviors in rats. Illumina 16S rRNA gene sequencing on rat feces showed CUMS increased the relative abundance of Firmicutes (60.31% vs. 48.09% in Control, p < 0.05) and Lactobacillus genus (21.06% vs. 6.82% in control, p < 0.05); FLX and CUMS increased Bacilli class (20.00% similar to 24.08% vs. 10.31% in control, p < 0.05). Conclusion Collectively, our study showed that both CUMS and FLX changed the compositions of gut microbiota in rats. FLX and CUMS distinctly regulated the gut microbiota in depressed rats.