Wow, you answered my exact question. I too believe I have a case of blastocystis (waiting on confirmation tests). I was thinking of taking probiotics during and after treatment but heard the same as you that it might very well feed the protozoa. Probiotics seem to be the new "it" thing out there, a cure for ALL your ills. I think in a few years we might hear that in fact they too have some side effects, just as we did with Antibiotics . As always, what may heal one person might hurt another :( as frustrating as that is...