Many probiotic Bifidobacteriacea contains an active tetW that renders the cells resistant to tetracycline. This presents a theoretical risk of a horizontal transfer of functional antibiotic genes. The present invention relates to novel tetracycline-sensitive strains of the well-known probiotic Bifidobacterium animalis subsp. lactis strain BB-12® and the use of such novel strains for the preparation of a food or feed product or a dosage form comprising viable organisms.
