Kefir is milk that has fermented into a yogurt like consistency giving it probiotics. It gives soap natural AHA (alpha-hydroxy Acid), which clears dead skin cells.Kefir also causes skin to hold onto more water leaving softer skin. The soap is really creamy while having a good lather. If you get the one with oats, you get extra exfoliation with the scubbiness that comes with it. The one without oats is better for people with any rashes or sensitive skin that would prefer no extra buffing.