Heat-killed Enterococcus fecalis (EC-12) supplement alters the expression of neurotransmitter receptor genes in the prefrontal cortex and alleviates anxiety-like behavior in mice

Small intestinal flora graft alters fecal flora, stool, cytokines and mood status in healthy mice

“…The role of the genus Lactobacillus reported previously might be one of the reasons for the effects induced by SIMT in our study. Other gut microbiota, such as the Enterococcus faecalis (OUT804 in our data), were previously linked to decreased anxietylike and depressive-like behaviors in mice (Takahashi et al, 2019;Kambe et al, 2020). Besides, the possibility should not be ruled out that the strains that did not show differences among groups also had an impact on the observed indicators because the interaction between intestinal microbiota and the body is undoubtedly extremely complex (Arumugam et al, 2011), involving a series of physiological and biochemical mechanisms and processes.…”

Probiotics, Prebiotics and Postbiotics on Mitigation of Depression Symptoms: Modulation of the Brain–Gut–Microbiome Axis

“…Anti-anxiety effects of heat-killed bacteria were also observed in healthy rodents [85,157]. Male C57BL/6J mice were fed with heatkilled Enterococcus faecalis strain EC-12 (EC-12) (diet enriched with 0.125% concentration of heat-killed EC-12 for 4 weeks) [85]. Behavioral tests (open-field, elevated plus-maze and forced swim tests) showed that mice supplemented with EC-12 had decreased anxiety-like and depression-like behavior [85].…”

“…The International Scientific Association for Probiotics and Prebiotics proposed the following definition of postbiotics: "a preparation of inanimate microorganisms and/or their components that confers a health benefit on the host" [81]. The concept of non-living microorganisms that could promote or preserve health is not new, other terms that have been used to describe such substances include "paraprobiotics" [82,83], "heat-killed probiotics" [84,85], "metabiotics" [86] and "bacterial lysates" [87]. In order to provide a clear definition, a panel of experts have defined the scope of postbiotics to be deliberately inactivated microbial cells, with or without metabolites or cell components, that contribute to demonstrated health benefits [81].…”

“…Additionally, gene expression in the nucleus accumbens, which is a stress-relevant brain region, was modulated by this postbiotic [156]. Anti-anxiety effects of heat-killed bacteria were also observed in healthy rodents [85,157]. Male C57BL/6J mice were fed with heatkilled Enterococcus faecalis strain EC-12 (EC-12) (diet enriched with 0.125% concentration of heat-killed EC-12 for 4 weeks) [85].…”

“…Male C57BL/6J mice were fed with heatkilled Enterococcus faecalis strain EC-12 (EC-12) (diet enriched with 0.125% concentration of heat-killed EC-12 for 4 weeks) [85]. Behavioral tests (open-field, elevated plus-maze and forced swim tests) showed that mice supplemented with EC-12 had decreased anxiety-like and depression-like behavior [85]. Moreover, EC-12 supplementation modified the gene expression profile in the prefrontal cortex and significantly increased Butyricicoccus and Enterococcus composition in the gut compared to the control group [85].…”