Antimicrobial peptide AP2 ameliorates Salmonella Typhimurium infection by modulating gut microbiota

Endogenous antimicrobial peptides/proteins contribute to reshape a healthy gut microbiota which play benefit roles in anti-inflammation and pathogen colonization resistance. Salmonella infection is one of the most frequently reported bacterial diseases worldwide. Manipulation of the gut microbiota through exogenous antimicrobial peptide may protects against Salmonella enterica colonization and improve clinical outcomes. In this study, results showed that oral administration of antimicrobial peptide AP2, an optimized version of native apidaecin IB (AP IB) had a protective effect against ST infections in mice indicated by alleviated ST-induced body weight loss and reduced the serum inflammatory cytokines. 16S rRNA-based analysis of microbiota from the cecum content showed that AP2 altered gut microbiota by significantly increasing the proportion of Bifidobacterium and decreasing Akkermansia at the genus level. Furthermore, the transplantation of fecal microbiota from AP2-treated donor mice, instead of control mice, significantly reduced caecal damage caused by ST. In conclusion, these findings hightlighted one of novel action mechanisms of exogenous antimicrobial peptide on ameliorating Salmonella Typhimurium infection by modulating gut microbiota.