Initial Posting: 11/11/2014    Last Update: 5/30/2019
Answer: Although yogurts, such as Greek yogurt, may be teeming with organisms used as starter cultures (such as Lactobacillus bulgaricus and Streptococcus thermophilus), these are not necessarily "probiotic" organisms, i.e., those which seem to survive passage through the stomach and populate the gut for beneficial effect.
If you want probiotic organisms, you'll need to get them from a separate product or purchase a yogurt to which probiotic organisms have specifically been added (check the label). Many clinical studies of probiotics in Asia and Europe have, in fact, been conducted with yogurts and other cultured dairy products to which probiotics have been added. You can read about these studies, learn more about probiotics, and see our tests of popular probiotic products in the Probiotics Supplements Review.