Compositions are provided according to the present invention which include microorganisms and/or products of microorganismal metabolism. Humans and other animals have difficulty gaining nutritional benefit from many highly abundant plant materials, such as cellulose. A traditional means of gaining the benefit of these nutrients has been through the cultivation of animals capable of utilizing such materials, subsequently consuming their meat and milk products. However, raising such animals is time consuming and expensive. Compositions and methods according to the present invention allow circumvention of the use of these cultivated animals for meat and milk. Microorganisms are isolated from an animal which is a traditional source of food for a second type of animal, such as humans or pets, in order to produce compositions of the invention. Such compositions provide nutritional benefit to the consumer.