Fonseca, Inês M.Mateus, CristianaVieira, AlexandreDomingues, FernandaManageiro, VeraOleastro, MónicaFerreira, Susana2026-01-222026-01-222025-11-28J Appl Microbiol. 2025 Nov 28;136(12):lxaf303. doi: 10.1093/jambio/lxaf3031364-5072http://hdl.handle.net/10400.18/10736Aims: Arcobacter butzleri, a widespread bacterium linked to gastrointestinal disease, can bypass host colonization resistance mechanisms; however, its response to short-chain fatty acids (SCFAs) remains poorly understood. This study investigated the impact of SCFAs on A. butzleri ’s survival and virulence. Methods and results: Eight A. butzleri isolates were assessed under varying concentrations of individual SCFAs and mixtures (m-SCFAs). Higher SCFAs concentrations inhibited bacterial growth in a strain-dependent manner. Transcript analysis of putative virulence genes revealed upregula- tion of ciaB and flaA across most m-SCFAs concentrations, while luxS expression increased at 90 mM. SCFAs generally reduced bacterial motility, with sodium propionate reducing motility but enhancing biofilm-forming ability in the model strain. Additionally, SCFAs exposure decreased the ability of A. butzleri to adhere to and invade the Caco-2 intestinal epithelial cell line. Whole-genome sequencing of the eight A. butzleri isolates revealed extensive genetic diversity, particularly in virulence- and stress-associated genes, although consistent genot ype/phenot ype correlations were not observed. Conclusions: Altogether, these findings demonstrate that SCFAs modulate A. butzleri survival and virulence, providing novel insights into their significance in shaping pathogen behaviour and host-pathogen interactions.engArcobacter ButzleriAdhesion and InvasionBiofilmsMotilityShort-Chain Fatty AcidsVirulence GenesResistência aos AntimicrobianosInfecções Gastrointestinaisjournal article10.1093/jambio/lxaf3031365-267241384789