Evaluation of the antimicrobial and intestinal integrity properties of boric acid in broiler chickens infected with Salmonella enteritidis: Proof of concept

The objectives of the present study were to evaluate the antimicrobial effect of boric acid (BA) on Salmonella enteritidis colonization, intestinal permeability, total intestinal IgA levels, and cecal microbiota composition in broiler chickens. For this purpose, sixty day-old-chicks were randomly allocated to one of two groups: 1) non treated control group and 2) 0.1% (w/w) BA in feed. All chicks were challenged with 10(4) cfu of S. Enteritidis per bird at 1-d old. On day 3 and 10 post-challenge, samples of crop and ceca-cecal tonsils (CCT) were aseptically collected to evaluate overall aerobic and lactic acid bacteria, as well as S. Enteritidis recovery. Blood and intestinal samples were also collected to evaluate intestinal permeability and total intestinal IgA production, respectively. On day 10 post-challenge, the concentration of S. Enteritidis in crop and CCT significantly decreased (P < .05) by 2.60 log10 and 5.26 log10, respectively, in the BA group compared to the control group. Furthermore, chickens treated with 0.1% BA had a significant reduction in serum fluorescein isothiocyanate dextran (FITC-d) concentration and lower total intestinal IgA levels when compared to the control group. Interestingly, in the microbiota analysis, only the abundance of Actinobacteria phylum was significantly lower in the BA group in comparison with the control group and significant differences in beta diversity were also observed between comparing groups. The results of the present study suggest that BA could maintain intestinal homeostasis, as well as the balance in the microbiota due to its effectiveness in controlling S. Enteritidis infection.