There are 2 very important factors in determining which probiotic is better than another:
1: HIGH QUANTITY OF BENEFICIAL MICRO-ORGANISMS
The more the merrier! Ideally one should be getting several billion live “CFUs” or “colony forming units” on a near daily basis in any good probiotic
2: A LARGE DIVERSITY OF STRAINS
Although very hard to find, a really great probiotic will be a “broad spectrum” probiotic containing very many different strains and species of beneficial bacteria, just as in our own digestive systems. This contrasts with most of even the best live yogurts and supplements which are typically based on just 2 strains.
We know of no better probiotic available than natural kefir, the key ingredient of “Kefi”. Not only does kefir typically contain several billion live microbes per teaspoon, it also contains literally DOZENS upon dozens of different strains and species of beneficial bacteria and even beneficial yeasts as well, helping to keep Candida and thrush in check. In other words, while most other probiotic products artificially boost the populations of just 1 or 2 strains, kefir is a BROAD SPECTRUM PROBIOTIC.