CFU
Colony-Forming Unit - the count of viable microbes, used to verify probiotic potency claims.
A CFU (colony-forming unit) is the standard count of viable, reproducing microbial cells - the unit used to label probiotic potency (e.g. "50 billion CFU"). CFU enumeration verifies the live count actually matches your label.
Standard plate counts only detect cells able to divide; flow cytometry or PMA-PCR distinguish live from dead cells. Because viability declines over shelf life, "50 billion at time of manufacture" and "50 billion at expiry" are very different claims - and the gap is a class-action magnet.
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