I've just had a lymph infection and the doctor strongly suggested that I took a probiotic along with the pretty strong antibiotics he prescribed. He said it would minimise the stomach problems associated with the antibiotics. So their not total quackery.
I can see the point of taking them if you've had a round of strong AB's... But as part of a normal day to day diet? Assuming you already have a batch of the little beauties working away in your tract what's the point in filling them up (and Yakuts pockets) every day?? Fat doc - I have a spectacular reaction to amoxycillin.. Large hives over the whole body apart from face and hands.. Scary stuff...