I have experimented a little with a few drops of Miracle-Mineral-Supplement as an enema. I also send in Genova microbiology tests at least once a month.
MMS has never reduced my bifidus and e.coli strains (beneficial flora) one bit. (I'm not sure about lacto strains because yeast thrives on these, so I usually have no growth in the final 'end' stage product)
I think there will be quite a difference between firing up freeze-dried yogurt starter cultures vs. thriving bacteria.
In vivo in my experience is not effected, but then again Science hardly knows about all the strains of a full flora composition.