I make fermented cabbage (sauerkraut) but I have to be honest in saying that I stopped eating it routinely. I may start up again with only plain water without the salt as I preferred it without.
I would think most of the bacteria is destroyed from stomach acid whether it be in pill form, powder or real food. I think the actual quantities required are far in excess of what is sold in pill form. There are thousands of anecdotal cases of people managing severe digestive disorders and other disease through 1-2 capsules. What ever changes have to be manageable, consistent and long term.