I'm a huge advocate for taking probiotics to maintain a healthy gut flora. I suppose for those that eat enough fermented foods (kimchi, kefir, etc.) then you may happily skip taking them, but I prefer knowing that I'm getting at least a good baseline of what I need in supplement form each day. They question becomes - how to select and buy them?
Vary the Strains
Unless you have a gastrointestinal disorder or irritable bowel disease (in which case, please contact myself or another RDN that can help guide your gut health!), I typically recommend a range of strains instead of just finding one strain on bacteria within the probiotic. There is no magic number for # of strains that should be involved but the most commonly found ones include L. acidophilus, B. bifidum, S. boulardii, and L casei.
All About the CFU
CFU = Colony Forming Units. Despite the fact that the recommended minimum levels continue to creep up slowly, I consistently recommend at least 8 billion CFU. This is a range that is both safe and effective. Something as low as 1 or 2 billion might not make a huge difference in gut health and 8-20 billion safe for the average, healthy adult. Sound like too much? To put it in perspective, therapeutic doses start at about 112 billion and go up from there.
Storage and Resources to Purchase
Keep in a cool, dry place. The fridge is often the best option! I keep min in the door which helps me to remember to take it in the morning...
In good health, enjoy!