The strain(s) of probiotics makes a difference

I was just watching my local news today and during "health Beat" they were discussing with a GI that it's key that with treating IBD the strain of probiotics used are key, since some strains can actually cause D, for example Activia yogurts....it was also mentioned that 10 billion was the minimum amount that should be taken daily, anything less would be less sufficient...so I couldn't find the story on their webpage yet (like not downloaded) but I did a google search and this is what I found...

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1774052/

http://www.functionalingredientsmag.com/article/Formulations/probiotics-strains-matter.aspx

:)

Thats a scary conclusion reached in this study and makes me want to reconsider throwing away good money and possibly exposing myself to bad bactieia or other contamination.

I just finished an antibiotic and need to start on probiotics. After my c-diff infection last fall, the doctor told me to take culturelle. But it doesn't look like it has enough of what I need. I've also tried primal defense in the past and at the time, that and the dietary changes seemed to have a good effect although maybe it was just a coincidental remission. I've been flaring badly during the past year or so and need to get things under control if possible.

Are doctors the best source for finding a probiotic or should I just go down to the local vitamin shop and see what they recommend? I'm so confused and don't want to waste money on something useless. Is there a favorite among this group who do use them?