RNAseq analysis from LPAIV H1N1-infected CLEC213 cells further revealed butyrate’s modulation of infection-related pathways, notably by suppressing HIFs, TGF-β, p53, and NF-κB signalling pathways, emphasising its role as a negative regulator of inflammation during H1N1 infection in chicken lung epithelial cells (Supplementary Fig. 9a). Here, TGFB1 is linked to infection.