As I mixed up my post workout smoothie & started surfing AM, I started to wonder if anybody else ever used kefir. If you don't what it is, it's basically cultured milk. You can buy it commercially pre-made at the store or you can make your own, which is what I do. Way cheaper & healthier in my opinion. Almost twice the protein as regular milk & billions of healthy probiotics.. What more could you ask for! Feel free to chime in if you use or have tried it.