I recommended Infantis and Bifidus strains in particular for quite a number of reasons including their capacity to biosynthesize and interconvert folates, their efficacy in lowering the inflammatory response, their ability to permanently colonize, their strong association with the infant microbiome, and their apparent susceptibility in some disease states.
I realize this is an ancient thread, but if @Vegas stops by, could you provide a reference or references that bifidus permanently colonizes the gut? All I can find is that it (and many other strains) need to be taken often or they're gone from the intestinal tract within 1-4 weeks.
Thanks in advance.