Organic acid blend boosts butyrate and limits pathogens in an exploratory ex vivo chicken caecal model

Organic acid blends are being explored as alternatives to antibiotics in poultry production because of their antimicrobial and microbiota-modulating properties. This study examined whether a subinhibitory concentration of AuraShield could stimulate Faecalibacterium prausnitzii-associated butyrate production while reducing colonisation by Salmonella enterica serovar Typhimurium and Campylobacter jejuni in an ex vivo chicken caecal model. Minimum inhibitory and bactericidal concentration assays identified 0.125% AuraShield as a subinhibitory dose. In whole caeca incubated for 24 h under microaerophilic conditions, AuraShield promoted F. prausnitzii growth and increased butyrate production. Co-incubation with F. prausnitzii reduced pathogen loads, and this effect was further enhanced by AuraShield. The treatment also reduced caecal expression of the inflammatory chemokines CXCLi1 and CXCLi2, as well as the oxidative stress marker ROMO1. In complementary co-culture experiments, AuraShield increased butCoA expression and stimulated butyrate release by F. prausnitzii in a dose-dependent manner. Comparative experiments with inulin showed that AuraShield promoted butyrate production and reduced pathogen growth at levels comparable to, or greater than, those of the prebiotic control. Overall, these findings suggest that AuraShield may support beneficial bacterial activity under ex vivo conditions. Further in vivo studies are needed to confirm its potential under field conditions.