Chronic lung inflammation and infections contribute to disease progression in cystic fibrosis (CF) patients. This project aims to study a novel class of compounds, the indoles, to overcome the wide spread antibiotic resistance and the toxicity of anti-inflammatory drugs. Indoles are naturally produced by bacteria and are reported to act as potential anti-virulence compounds against antibiotic-resistant pathogens, moreover would modulate inflammation, thus acting on both the host and its microbes. They belong to the so called “postbiotic” family, i.e. microbial-derived metabolites. The indole-3-aldehyde (3- IAld), produced by Lactobacilli, has recently been shown to preserve immunophysiology at mucosal surfaces while inducing antimicrobial resistance. The researchers intend to develop a 3- IAld inhalable dry powder for pulmonary drug delivery and assessment of pharmacokinetics in CF mice; then to perform in vitro and in vivo studies with murine and HBE cells as well as mice with the F508del mutation. Their final goal is to provide proof of concept data about the activity of the indole derivative 3-IAld as a new therapeutic agent in CF.