As for the acidophilus supplement, don't quote me on this, but I believe the recommended dosage for this purpose is 10-40 million cultures per day for adults and 1-3 million for children (I use the powder for DD and mix it with yogurt). The size of the capsule doesn't matter, it's the amount of cultures it contains. This information should be on the bottle. I believe it is also best to start with the lower end of the range and work up if necessary. I've been taking 1 capsule with 20 million cultures the past few days but I might add another. I've been giving DD about 1.5 million per day in one dose.
Does that make sense? I will see if I can find the source for that information.