Abstract
Probiotics represent a possible strategy for controlling intestinal infections in livestock. Members of theWeissellagenus are increasingly being studied for health-related applications in animals and humans. Here we investigated the functional properties of twoWeissella cibariastrains isolated from cows reared in Kuwait breeding facilities by combining phenotypic with genomic analyses. W. cibariaSP7 and SP19 exhibited good growth in vitro under acidic conditions and in the presence of bile salts compared to the reference probioticLacticaseibacillus(formerlyLactobacillus)rhamnosusGG. Both strains were able to adhere to Caco-2 and HT-29 cell lines, as well as to mucin. The cell-free supernatants of the two isolates exhibited inhibitory activity towardsEscherichia coliATCC 25,922 andSalmonella entericaUC3605, which was ultimately due to the low pH of supernatants.W. cibariaSP19 showed a co-aggregation ability similar to that ofL. rhamnosusGG when incubated withS. enterica. Whole genome sequencing and analysis revealed that both strains harbored several genes involved in carbohydrate metabolism and general stress responses, indicating bacterial adaptation to the gastrointestinal environment. We also detected genes involved in the adhesion to host epithelial cells or extracellular matrix. No evidence of acquired antibiotic resistance or hemolytic activity was found in either strain. These findings shed light on the potential ofW. cibariafor probiotic use in livestock and on the mechanisms underlying host-microbe interaction in the gut.W. cibaria`strain SP19 exhibited the best combination of in vitro probiotic properties and genetic markers, and is a promising candidate for further investigation.