TLR4 and infection: In the study, C. butyricum suppressed inflammation by down-regulating TLR4, MyD88, and NF-κB-dependent pathways in chickens with SE infection on day 6 post-infection, which is consistent with the report that indicated that probiotics can decrease pro-inflammatory cytokine levels by inhibiting the expression of TLR4, MyD88, and NF-κB-dependent pathways in LPS-induced macrophages and in mice (Song et al., 2015; Yi et al., 2015).