VSL3 DS is the one my GI doctor prescribes. It is a "medical food". In the DS form it is prescribed. In the regular form VSL, it can be purchased OTC. VSL3 contains 450 billion live lactic acid bacteria. The highest concentration of live bacteria for any probiotic. VSL3 DS has 900 billion live bacteria.
There is a good sticky on the IBS forum with more information on this probiotic. Many people on that thread had good success with the VSL 3. A web search will give you more information.
The main drawback for this probiotic is that it is quite expensive.
I take a probiotic also and find it helped me a little.
The best way I can control my acid refuux and heartburn is by losing weight. It happened 10 years ago when after a strict diet, 20 pounds thinner, I suddenly realised I hadn't had any heartburn for a while. Recently I (having regained about all of it back) began exercising regularly and am now down around 13 to 15 pounds --- and lo and behold, my acid reflux is entirely missing on some days, and only slight on others. I still take the probiotic anyhow. Hoping it stays gone.
I think taking them is helpful and not harmful as are many other acid reduceing types of pills.