Alex: My medical mafia's consensus is to be sure you use a mix with live bacteria, at least 10 billion of them, and to change your probiotic every month or so as your gut gets used to any given mix after a time. Many are designed and marketed for specialized issues.
Culturelle is one on the regular rotation in my house. VSL3 is another., LEF has several I use. Most anything fermented supplies probiotic bacteria. Braggs Apple Cider Vinegar, kefir, yoghurt are examples. If the mother of vinegar is still in the jar it's particularly good.
Here's a link to Dr. Oz guide to probiotics: [
www.doctoroz.com]
Gordon