How to Choose a Probiotic
Start with the intended use, then work backward to the exact strain and evidence. Bigger CFU numbers and longer ingredient lists are not automatically better.
1. Define the reason
There is no universal “best probiotic.” Evidence varies by health outcome, so identify what you are trying to accomplish before comparing labels.
2. Look for strain-level identification
Species names alone may be insufficient. When research is strain-specific, the alphanumeric strain designation matters.
3. Understand CFUs
CFU means colony-forming units, a conventional measure of viable microorganisms. A higher number is not proof of greater benefit; the relevant amount depends on the organism, formulation and evidence.
4. Check storage and expiry
Some products require refrigeration while others are shelf-stable. Follow the manufacturer's storage instructions and look for viability information tied to the end of shelf life when available.
5. Assess claims against evidence
NCCIH cautions that strong evidence for many proposed probiotic uses is lacking. Be skeptical of guarantees, especially for complex outcomes such as weight loss.
6. Consider your health context
If you are pregnant, immunocompromised, seriously ill, taking medication or managing a health condition, ask a qualified clinician before starting a supplement.