Furthermore, Bifidobacterium breve CCFM1025 significantly inhibited depression- and anxiety-like behaviors by mitigating HPA axis hyperactivity and inflammation, upregulating BDNF levels and downregulating c-Fos levels, raising the serotonergic system in the gut and brain of chronic stressed mice after 5 weeks [231]. This evidence concerns the gene BDNF and depressive symptom measurement.