Histone deacetylase (HDAC) and sirtuin 1 (SIRT1) regulates the modification mode of histone H3 [acetylation of histone lysine 9 (acH3k9), acetylation of histone 3 lysine 27 (acH3k27), and phosphorylation of histone H3 at serine s10 (pH3s10)] in the promoter region of antimicrobial peptides, which specifically increases the expression of intestinal AMPs and enhances their ability against bacterial infections (15–17). Here, HDAC9 is linked to bacterial infectious disease.