Probiotic characterization of indigenous lactic acid bacteria isolates from chickens to be used as biocontrol agents in poultry industry

Lactic acid bacteria (LAB) are used as probiotics to improve animal health and production. This study aimed to characterize and assess three LAB, Ligilactobacillus salivarius 1234C, Ligilactobacillus agilis 1235C and Enterococcus durans 12311C, isolated from chicken, as potential probiotic candidates to improve the production parameters of commercial poultry. Resistance to gastrointestinal conditions, growth in alternative culture media, antagonistic activity against Salmonella and mycotoxigenic fungi were investigated. Additionally, the strains were added to poultry feed to evaluate their in vivo effect. The three LAB showed high survival rates after sequential gastric and intestinal conditions, demonstrated bactericidal activity against Salmonella and were able to grow in alternative culture media. Also, ligilactobacilli strains exerted fungicidal activity against mycotoxigenic fungi. In vivo assay showed that dietary supplementation of a multi-microbe probiotic product with 10(7) CFU/ml significantly increased (p < .05) height: crypt depth ratio at 16 days compared to controls and promoted the highest average weight in chickens. Thus, three novel LAB strains with potential as probiotic properties have been characterized and could be considered probiotic candidates for animal production. Novelty impact statement It is important to find novel probiotic candidates to improve and complement current treatment strategies in the poultry industry. Three indigenous lactic acid bacteria from poultry were found to possess suitable in vitro probiotic properties. Moreover, the inclusion of these strains as a multi-microbe probiotic product in the diet of broiler chickens had no adverse effects on the general health status of broilers and showed a positive effect on the average daily weight at the final growth period.