I have used Bio K in the past for candida. It is NOT the same as Kefir. They are like twins with opposite polarization, or what they call race mates in Organic Chemistry. The direction in which they polarize light is opposite, one to the right the other to the left. This is imprtant because it governs its interactions with cells in the human body and the effects it will have. The properties of these so called race mates can be totally unsimilar even though structurally they may look the same.
Kefir is wonderful because you can make it yourself forever and ever. Once you start, you can use the part of the grains to start the next batch and so on.
You can make large amounts to use topically on your skin, acne, scalp, toe fungus, in douches, or in enemas.
Kefir gives a great boost to your immune system. It helps to alkalize and repopulate the intestines. It tastes quite a bit similar to bioK. It just a little bit runnier I think. You can add stevia or strawberries to give it flavor. Any fruit is fine. I added fresh red grape juice to it. That was yummy.
BioK is expensive after a while. I had to stop. I can't say what the difference was exactly in my body because I have been changing my diet drastically now and doing livr flushes and other cleanses, so the comparison would not be fair.