While it is true that change in oral flora from (eg) broad-spectrum
antibiotic use can lead to yeast superinfection, and that  sources of
so-called "friendly bacteria" may be an aid to re-establishing a more
normal flora afterwards, it is a leap to think that taking a few pills
of lactobacillus will get rid of yeast infections.  We routinely see
these conditions wax and wane spontaneously in our patients, sometimes
depending upon weather, nutritional status, denture wearing, or for no
discernable reason.
    As for how many will survive in the stomach, I would guess it depends
upon the specific variety of bug, but I'd guess most would not survive.

Steve

Consumer's Reports has an article about this in the current issue.
They tested a lot of these tablets and found that half had far fewer
live bacteria than claimed on the label, and the number declined
rapidly with time.  They recommended yogourt as a much economical and
reliable source of these "probiotic" bacteria.

Whether taking these tablets "drove the Candida from the entire system"
or the infection resolved on its own anyway, low fat yogourt is a
nutritious food that even people with lactose intolerance can usually
eat.  CU found that a serving of yogourt had 15 to 155 *billion* live
bacteria (colony forming units), while the supplements tested at 20
million to 70 billion CFUs per daily dose.