CFU Is a Measurement of Good Bacteria and Yeasts in Probiotics

CFU is an acronym (type of abbreviation) commonly seen on products containing probiotics. It stands for "colony forming unit" and is a measurement of the good bacteria and yeasts inside.

A colony forming unit is a bacteria or yeast that is capable of living and reproducing to form a group of the same bacteria or yeasts.

Microbiologists use colony-forming unit to describe the number of active, live organisms instead of the number of all the bacteria - dead, inactive and alive - in a laboratory sample. Only the viable organisms are considered to be probiotics. "Viable" means that the microbes are capable of living under the proper circumstances.

Other Ways to See CFU on Products

You may also see it listed as CFUs - colony forming units. Most probiotic supplements in capsule or tablet form will state the number of colony forming units in the capsule or tablet. Or, if more than one capsule or tablet is the recommended serving size, then the colony forming units listed may be the total in the serving size. The only way to know for sure is to read the package.

Unless individually packaged, most powder probiotic supplements will have a recommended serving size listed and then the colony forming units in that serving size. For example, 1/4 teaspoon may contain 100 billion colony-forming units. Taking a consistent amount of 25 billion, as one-sixteenth of a teaspoon, may be difficult, unless you use special measuring spoons.

Another way the information may be presented is colony-forming units per gram or per millilter, meaning colony forming unit per unit of measure, or how many capable-of-living microbes are in a certain measurement. In these cases, you must look at the serving size in g (grams for a solid) or ml (milliliters for a liquid) and perform a mathematics equation. Multiply the colony forming units per gram or per milliliter by the number of grams or milliliters in the serving size to get the total number of colony forming units.

If the CFU/g is given, but no indication of how many grams are in a serving size (not just how many capsules), then that specific information is useless. You need to know how much of a product is recommended by the manufacturer and/or the quantity supported by research to know if the dosage is right for you.

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