I ordered the Body Ecology Kefir Grains Starter kit, (In responce to the Link you posted). I made Coconut milk Kefir with it and had a bad response, not Die-off. Its has Nutrional Yeast(saccharomyces boulardii). Im trying new Kefir from a local store, without any stated yeasts, and will see how that goes.
I stay away from all raised breads, as they give me bad reactions, and digestive issues.