Isolation, identification and selection of beneficial canine homologous lactic acid bacteria by their potential probiotic characteristics.

Companion animals have become an increasingly important part of human life, consequently, there is a significant increase in the demand of natural food ingredients and functional foods in order to improve their health and well-being. Probiotics have been used in humans and production animals and have recently attracted the focus of the pet industry. Therefore, the main objective of this work was to isolate, and survey the different beneficial properties of lactic acid bacteria (LAB) strains from dogs, in order to advance in the design of probiotic formula that would be beneficial for canine health. One hundred presumptive LAB isolated from mother's milk and faeces of canine puppies and adult dogs were selected and their surface, enzymatic activities and adhesion properties were studied: 40% showed high or medium hydrophobicity, 13% self-aggregation, 20% cellulase activity and 19% feruloyl esterase activity. Based on the results, 60 LAB were pre-selected and their biofilm formation was evaluated in media without Tween 80, and their EPS production on MRS with glucose, sucrose or lactose. Also, 60% of the isolates grew on folate-free medium, while 53% on medium lacking riboflavin. The genetic identification of 30 isolates indicated: 4 L. johnsonii, 2 L. salivarius, 2 L. plantarum, 2 S. thoraltensis, 2 P. acidilactici, 7 E. canintestini, 4 E. faecalis, 6 E. faecium and 1 E. durans. Finally, ten of the selected LAB strains evidenced adhesion ability to eucaryotic cells close to 70%. This work supports the selection of LAB strains with the best characteristics through laboratory assays, and to define those sharing properties, in a way to define their optimal combinations, to further advance in the design of probiotic formulas containing homologous strains for the health of canines.