I always give probiotics to my goats when they go through any abnormal stresses and when I have to give antibiotics... I always wondered if it was pointless to give probiotics when they were on antibiotics because wouldn't the meds wipe out the new flora you were introducing to the gut as well as the established flora? Well, I am on a very powerful antibiotic for a dog bite. I HAVE to take it, it is not negotiable. One of the most common side effects to this drug is thrush, cramps, nausea, diarrhea---which can escalate to a form of ulcerative colitis caused by this drug wiping out all flora except the one which causes the ulcerative colitis---and the drug for that bug is one I am allergic too! You are not even supposed to take this antibiotic if you have ever been diagnosed with ulcerative colitis---and I battled that condition as a young adult, as well as severe thrush in every membrane of my body. So I was really apprehensive about taking this. I am allergic to all the other drug choices. So, remembering what I do for my goats, I got myself some good probiotics at the local health food store. (I am also eating yogurt, but the benefits of that are very slight!) I am very happy to report that although I do have some stomach discomfort, and loss of appetite, my bowels have been wonderfully normal, I have no sign of thrush, and I can literally feel the comfort spread through my abdomen within an hour of taking the probiotics...I take it 1 to 2 hours after the antibiotic. So, if, like me, you have ever wondered about the value of probiotics, wonder no more! I am sold!