What Are Probiotics?
Probiotics are live microorganisms intended to provide health benefits when consumed or applied to the body. The important details are which microorganism, which strain, what dose and for what purpose.
Where probiotics are found
NCCIH notes that probiotics occur in fermented foods and dietary supplements, among other products. Common groups include Lactobacillus and Bifidobacterium.
Not all probiotics are equivalent
Different products can contain different species and strains, and their effects can differ. A label that says only “probiotic blend” tells you less than one that identifies organisms precisely.
What evidence supports
Research is condition-specific. NCCIH says probiotics have shown promise for some uses but that much remains unknown about which probiotics help, how much is needed and who is most likely to benefit.
Safety
Healthy people often tolerate probiotics well, but safety data are not complete. Risks can be higher in people who are seriously ill or immunocompromised. Ask a clinician about individual risks.
Next guides
How to choose a probiotic →
How to read a probiotic label →
Probiotics and body weight →