Faecalibacterium prausnitzii (ATCC 27766) has preventive and therapeutic effects on chronic unpredictable mild stress-induced depression-like and anxiety-like behavior in rats.

The realization that the microbiota-gut-brain axis plays a critical role in health and disease,including neuropsychiatric disorders, is rapidly advancing．An abundance of preclinical studies have shown that psychobiotics acting via the brain-gut-axis can affect brain development, function and behavior. Here we tested whether potential psychobiotics Faecalibacterium prausnitzii (ATCC 27766) has anxiolytic and antidepressant-like effects and reverse the impact of chronic unpredictable mild stress (CUMS) in rats. The experiment was divided into two phases, the first stage was CUMS procedure period and the second stage was convalescence period. SD male rats were administered Faecalibacterium prausnitzii for 4 weeks prior to testing during each period. Behavior, growth status, SCFAs produced, plasma cytokine, endocrinology and bone mineral density (BMD) were assessed. Our findings indicate that the administration of F. prausnitzii had preventive and therapeutic effects on CUMS-induced depression-like and anxiety-like behavior. In addition, F. prausnitzii administration could significantly prevent the reduction of the whole-body, femur and tibia BMD during the recovery phase. Moreover, the growth status of rats fed the F. prausnitzii was better than the rats by CUMS. And F. prausnitzii administration led to higher levels of SCFAs in the cecum and higher levels of cytokines interleukin-10 (IL-10) in the plasma, prevented the effects on corticosterone, C-reaction protein and cytokines interleukin-6 (IL-6) release induced by CUMS, changes that were associated with the effects seen on behavior. These results provide further evidence that gut microflora play a role in anxiety and depression. Subject to the confirmation of these results, probiotics might offer a useful novel therapeutic approach to neuropathological disorders and/or as adjunct therapies in psychiatric disorders and support the recent broadening of the definition of psychobiotic. Finally, this study supports F. prausnitzii has significant potential as a psychobiotic.