I have used kefir for improving digestion. I did not notice a change in my skin.
I am using the supplement okra-pepsin as a small intestine cleanse. Bowel Cleanse is vital as well, I have used Oxypowder with great success. I dislike the P&B shakes, myself, but they are more affordable.
Be sure to check out the R and RN messages for lots of more info. It is worth the time to read, read, read.