Characterization of "microbiome-metabolome-immunity" in depressed rats with divergent responses to Paroxetine.

OBJECTIVES

Selective serotonin reuptake inhibitors (SSRIs) are the first-line anti-depressants. Unfortunately, about 30 % depressed patients do not effectively respond to SSRIs. It is still unclear that the gastrointestinal characteristics of responders and non-responders, and the differences.

METHODS

Herein, we characterized gut microbiome and metabolome of depressed rats with differential responses to Paroxetine (PX) by 16S rRNA sequencing and H NMR-based metabolomics, respectively. On top of this, we constructed both inter- and inner-layer networks, intuitively showing the correlations among behavioral indicators, immune factors, intestinal bacteria, and differential metabolites.

RESULTS

Consequently, we found that depressed rats differently responded to PX, which could be divided into PX responsive (PX-R) and non-responsive (PX-N) groups. Firstly, the depressive behaviors of PX-R rats and PX-N rats significantly differed. Meanwhile, inflammatory balance was also characterized for depressed rats with different responses to PX. Overall, PX-R rats and PX-N rats exhibited differential gut microbiome and metabolome, including intestinal structures, intestinal functions, metabolic profiles, metabolites, and metabolic pathways.

LIMITATIONS

Metabolites that identified by metabolomics based on H NMR are not comprehensive enough.

CONCLUSIONS

Taken together, our study demonstrated that gut microbiome and metabolome, as well as related functions, are of significance in differential responses of depressed rats to PX, which might be novel insights in uncovering the mechanisms of differences in efficacies of antidepressants.