Selenomethionine attenuates Klebsiella pneumoniae-induced jejunal injury in rabbits by inhibiting the TLR4/NF-κB pathway.

Klebsiella pneumoniae (KP) infection often causes diarrhoea and intestinal barrier damage in young rabbits. The objective of this study was to explore whether selenomethionine (SeMet) can attenuate the jejunal injury caused by KP in rabbits. Therefore, we investigated the protective effect of SeMet by performing haematoxylin-eosin (HE), alcian blue periodic acid Schiff (AB-PAS), proliferating nuclear antigen (PCNA), TUNEL and immunofluorescence staining. In addition, the concentrations of Interleukin-1β (IL-1β), Interleukin-6 (IL-6), Tumor necrosisfactor-α (TNF-α) and Interleukin-10 (IL-10) in the jejunal tissue were detected by enzyme-linked immunosorbent assay (ELISA). The results showed that after KP infection, the productivity of rabbits decreased, and the mucosal barrier of the jejunum was damaged. Moreover, KP induced jejunal inflammation, activated the TLR4/NF-κB signalling pathway, and promoted the expression of the IL-1β, IL-6, and TNF-α. In addition, KP increased the apoptotic response of intestinal cells and upregulated the expression of caspase-3 and caspase-9. SeMet pretreatment significantly decreased the degree of intestinal epithelial cell apoptosis. Therefore, we showed that SeMet can reduce inflammation and enhance intestinal barrier function to improve the production performance of rabbits infected with KP.