Antimicrobial peptides (AMPs), also known as host defense peptides (HDPs), exist widely in all classes of life, contributing not only to immune responses, mainly to bacterial infections, but also modulate the inflammatory response by regulating cytokines, chemotaxis, apoptosis and wound healing. Human HDPs contain three main components, namely human α-, β-defensins (HAD and HBD) and cathelicidin (LL-37). HDPs have a broad spectrum of activity against Gram-positive and negative bacteria, fungal species and viruses [1-4]. HBDs are small cationic amphipathic peptides with a beta-sheet structure and a signature motif of six cysteines [5]. While LL-37 has its two consecutive leucine residues at the amino terminus and 37 amino acids, so it was named accordingly [6]. In addition to their ability to kill bacteria similar to antibiotics, HDPs can also naturalize endotoxin produced by gram-terminal bacteria. negative bacteria, thus limiting the inflammatory reaction in the host [7]. Furthermore, with the difference in mechanisms compared to antibiotics, HDPs will cause less toxicity towards host cells and have a low risk of microbial resistance [8]. HDPs can be induced by various factors. Rather than pathogens, some dietary resources such as fatty acids, histone deacetylase (HDAC) inhibitor, curcumin, vitamin D3, zinc and disaccharides are reported to have HBD1 and LL37 induction activities, thus stimulating HDPs (3.9-11). These results made possible the therapeutic possibility of a HDP-inducing drug and treatment. Fatty acids are constructed by a chain of varying amounts of carbon atoms attached to hydrogen atoms. Fatty acids can be classified into three groups based on the number of carbon atoms: short fatty acids (SCFA) ≤ C5, medium chain fatty acids (...... middle of paper ..... . had a higher induction effect on HBD1 than their counterpart at the same concentration (Figure 3), with the maximum expression observed at 5-phenyl valeric acid (C5) (Figure 3). ). Effects of HDAC inhibitors on HBD1 and LL-37 inducing activities thereby regulating gene expressions. Butyrate has been reported as a non-competitive and reversible inhibitor of histone deacetylases (HDACs) [19-21]. Other HDAC inhibitors, such as sodium valproate, sulforaphane, apcidin, etc., have been examined as gene expression promoters [22-25]. on the expression of HBD1 and LL-37 induced by seven HDAC inhibitors (Figure 4).