Randomization and masking
Subjects were randomized to the two study arms in the order of their enrollment in the study using a computerized randomization list with a random block size of four. The study products were packed into sequentially numbered containers labeled by a BioGaia AB employee not involved in the study. This person also created and controlled the randomization key which was not revealed until all laboratory analyses were completed. Allocation was revealed for statistical analysis. The investigators and study participants were blinded to the group identities throughout the study.