In my case it was Renew Life. I sent them an email telling them my experience, and this was their response:
"Thank you for contacting Renew Life. Only certain strains can be cultured, ours cannot. Our Ultimate Flora Daily Care Probiotic does contain 15 billion live cultures. The 15 billion is considered a maintenance formula for those between the ages of 15-49. We recommend higher potencies for those dealing with digestive and immune system issues for balancing the body."
I responded by asking: "If I may ask, why can't it be cultured? How is it going to help me if
the bacteria don't grow?"