The growth behaviour of the probiotic strain Bacillus cereus var. toyoi in the gastrointestinal tract of broiler chicken and suckling piglets was evaluated. The strain germinated rapidly in intestinal samples from both animal species. Less than 10% of spores were recovered from the chicken crop and piglet stomach, respectively. Lumen samples and mucosal tissues from the hind gut of piglets displayed increasing colonization of the probiotic strain throughout the trial period. After oral administration of vegetative cells to broiler chicken and weaned piglets, sporulation was detected in all intestinal samples. The distribution of spore CFU indicated repeated germination and sporulation during the intestinal passage in piglets. B. cereus var. toyoi was not able to colonize the intestinal tract of both animal species. However, the probiotic strain was detected in suckling piglets before uptake of B. cereus var. toyoi supplemented feed. It is concluded that B. cereus var. toyoi germinates rapidly in broiler chicken and piglets, which is a necessary prerequisite for its possible probiotic effects. Germination and in vivo sporulation of vegetative cells indicated that the probiotic strain was metabolically active in the intestine of both animal species.