Nonanoic acid is a naturally-occurring saturated fatty acid with nine carbon atoms. Nonanoic acid significantly reduces bacterial translocation, enhances antibacterial activity, and remarkably increases the secretion of porcine β-defensins 1 (pBD-1) and pBD-2^[1]. In Vitro: Nonanoic acid upregulates endogenous host defense peptides to enhance intestinal epithelial immunological barrier function via histone deacetylase inhibition^[1].