Evidence-backed FAQ

What does CFU mean in probiotics?

Direct answer

CFU means colony-forming units, an estimate of the number of live microorganisms in a probiotic serving. There is no single CFU amount that is right for every strain, product, or outcome.[1], [2]

What the evidence shows

Human studies tested a wide range of amounts. Dose-response findings depend on the exact strain and endpoint; antibiotic-associated diarrhea has a clearer signal than many other outcomes.[1], [2]

Important limitations

A larger CFU number does not automatically mean a better product, and dose-response findings cannot be generalized across strains or conditions.[1], [2]

Related questions

  • Is more CFU always better?
  • Does the probiotic definition specify a number?

Read the full evidence summary

This FAQ is the concise answer. The linked research page provides the full study context, populations, doses, outcomes, and limitations.

Open the supporting research →

References

  1. A review of dose-responses of probiotics in human studies.. Beneficial microbes. 2017. Narrative review View source →
  2. Probiotics for the prevention of antibiotic-associated diarrhoea: a systematic review and meta-analysis.. BMJ open. 2021. Systematic review and meta-analysis View source →