“…Most probiotic strains are lactic acid bacteria (LAB), Gram-positive bacteria, facultative anaerobes or microaerophilic organisms and are generally catalase-negative. LAB are represented by the genera Lactobacillus, Enterococcus, Lactococcus, Leuconostoc, Pediococcus, Sporolactobacillus and Streptococcus, Weissella and others [82]. Additionally, there are criteria for the microorganism to become a probiotic; it must come from healthy animals, it must be neither pathogenic nor toxic, it must be able to adhere to the intestinal mucosa and persist in the GIT, it must be resistant to the hydrolytic activity of bile salts, it must be able to influence local metabolic activity, and it must have antagonistic ability against pathogens [81,83].…”