CFU

An ad in the middle of the tennis caught my attention.  It was for a gut medication that claimed some enormous number of CFUs — which I found were colony-forming units.  Our current preoccupation with the gut has led to more medications, more science jargon.  Apparently if you wish to count microbes you can count everything that is visible, that is, living or dead.  Colony counting involves culturing the microbes and then counting all the colonies in that culture.  The assumption is that each colony is produced by one microbe but this is not true.  Some will be produced by more than one cell so the reference is to a colony-forming unit with no assumptions about how many microbes clustered together to form it.  The CFU count  then has to be adjusted down to counter for units of more than one microbe.  It remains a rough estimate rather than an accurate count but it is some guidance.

The promise of probiotics is that they will introduce microbial good guys into your gut so you need to know if you are getting the best number of CFUs for your money.