Kefir is wonderful because of all the probiotics (if it is living) and kills candida. However, when it kills candida sometimes it can cause some serious die off. You will be dealing with enough die off, probably, from parasite cleansing. Personally I would say use yogurt with live acidophilus, and probiotics in supplement form for now. Try some prebiotics too, starting at smaller than recommended doses, or if you have abdominal discomfort wait until the bugs are gone to use prebiotics.
Later, consider the kefir for killing candida. Mho it kills candida better than anything, or at least it surely causes the most die off to let you know something is happening! And...I believe, also, that most people have candida though few suspect it and tests for it don't always reveal it.