Gut microbiome-derived propionate reprograms alveolar macrophages metabolically and regulates lung injury responses in mice

without a clear role for free fatty acid receptors (FFAR) or chromatin remodeling. These findings demonstrate that the gut‒lung axis can regulate resting lung metabolic tone through dietary fiber intake and the enrichment of SCFA-producing gut bacteria, as well as influence sterile and non-sterile lung injury responses. These results provide evidence to support the development of therapeutic dietary interventions to preserve or enhance specific aspects of host pulmonary immunity.