Probiotic bacteria and methods

A method for identifying specific bacteria to be used in a probiotic product, said method comprising the steps of:

• (a) comparing gastrointestinal tract bacteria in an antibiotic-fed and a no-antibiotic-fed animal using molecular techniques to identify bacteria present in the antibiotic-fed animal but not in the no-antibiotic fed animal;
• and
• (b) dentifying bacteria of step (a) present in the no-antibiotic-fed and present in lower numbers or absent in an antibiotic-fed animal.

A method for promoting growth in an animal, said method comprising the step of supplementing animal feed with viable cells of at least one bacteria selected from the group consisting of Clostridium irregularis, Clostridium lituseburense, Clostridium disporicum, Lactobacillus reuteri, Lactobacillus delbreukii, Lactobacillus aviarius, Lactobacillus crispatus, and Lactobacillus salivarius, in an amount sufficient to colonize the animal fed said animal feed, wherein said animal feed does not also comprise an antibiotic.

A method for identifying a test composition as a prebiotic for use in an animal feed, said method comprising the step of measuring intestinal microbial levels of clostridia in a gastrointestinal tract of the animal in the presence and absence of a test composition, whereby a test composition is identified as a prebiotic for use in an animal when the level of at least one of C. irregularis, C. lituseburense, C. disporicum, and Lactobacillus reuteri, Lactobacillus delbreukii, Lactobacillus aviarius, Lactobacillus crispatus and Lactobacillus salivarius is greater in a gastrointestinal tract of the animal in the presence than in the absence of said test composition.

A method for preventing necrotic enteritis in an animal, said method comprising orally administering an effective amount of viable cells of at least one species selected from the group consisting of C. irregularis, C. lituseburense, C. disporicum, Lactobacillus reuteri, Lactobacillus delbreukii, Lactobacillus aviarius, Lactobacillus crispatus, and Lactobacillus salivarius cells to the animal.

A method for assessing health of an animal, said method comprising the step of measuring C. irregularis, C. lituseburense and C. disporicum, Lactobacillus reuteri, Lactobacillus delbreukii, Lactobacillus aviarius, Lactobacillus crispatus, and Lactobacillus salivarius in a gastrointestinal tract of the animal or in feces of said animal, whereby.