An isolated Bacillus strain LSSAO1 is provided. When fed to a bird, this and other Bacillus strains described herein provide benefits to the birds. For example, administration of the one or more Bacillus strain can increase low G+C, gram positive bacteria in the gastrointestinal flora of the bird. These type of bacteria are increased by antibiotics and include beneficial Clostridium. Administration of the one or more Bacillus strain can also inhibit pathogen in the bird, such as E. coli, Salmonella, and Clostridium. These benefits can enhance feed conversion in poultry. Useful combinations of Bacillus strains and methods of using one or more Bacillus strain are also provided.