Hi dustler, Welcome to the Forum!
According to the best information we now have, MMS1 does not kill the good intestinal flora bacteria. I wouldn't take probiotics directly with MMS doses, but it's probably OK between doses, particularly when there's food in your stomach.
Also, I generally take supplements at the end of the day, so that my body can absorb them overnight while my body is doing its healing work.
I'm definitely not an expert in probiotics, but friends tell me that quality is important. A good natural food store should be able to advise you on quality. My energy healing friend gets me Original Medicine probiotics from Garden of Life.
In health freedom,
Bruce