Thanks Carol !!!! The American Gut project indicated that I had way less of certain gut bacteria and correspondingly way more than the average worldwide population. However, there is no interpretation offered and so I can only assume that my differences from the “norm” are not good rather than beneficial. Thus, I cannot select probiotics based on that analysis: it was of academic interest only (to me). MY GI doctor suggested that any probiotic I take should contain either Bifidobacterium" (B.) or Sacchromyces boulardi. (S. boulardi). I am currently taking OTC Ortho-Biotic which contains both. Some people suggest that refrigerated probiotics are more “potent” than others but I do not know if this is true. One such product is VSL#3 which also contains Bifidobacterium.