Bacillus clausii is a rod-shaped, Gram-positive, motile and spore-forming bacterium that lives in the soil. It is classified as probiotic microorganism that maintains a symbiotic relationship with the host organism. B. clausii spores are able to survive in the gastric environment and reach the intestine where they can germinate to vegetative forms. This characteristic is crucial for a microorganism used in oral bacteriotherapy. Bacillus clausii SNZ 1971 is a GRAS approved ingredient.