Twenty-five labelled supplements displayed the presence of
B. bifidum, but this was only detected sporadically (4 of the 25) and
always as dead cells. In these preparations different Bifidobacterium
species (for instance, Bifidobacterium adolescentis) were used. It is
likely that the abundance of literature supporting the efficacy in vitro
and in vivo of some B. bifidum strains may have drawn manufacturers'
attention in using these because of their health benefits. However, the
clinical or laboratory effects of one probiotic could not be assumed
and generalized to another, even within the same species