I have spoken with MANY, MANY people who have Blastocystis, including most that have actually rid themselves of this bug.
One thing is clear. Metronidazole (Flagyl) RARELY works, and I'm being kind. I know of NOT ONE PERSON cured of Blasto from Metronidazole.
S. Boulardii on the other hand, may help control the symptoms (mainly diarrhea, if present) though I have never heard of a cure from it. If there is more about this I would like to read it. When was the article published?
But I must say this again, Metronidazole is a waste of time in almost every case. That treatment is outdated and ineffective.
It seems only some clinics in Australia have the knowledge on how to actually get rid of this parasite.