Prebiotics vs. Probiotics: What’s the Difference?
Prebiotics and probiotics are related concepts, but they are not interchangeable. A probiotic is a live microorganism used in adequate amounts for a health benefit; a prebiotic is a substrate selectively used by host microorganisms that confers a benefit.
Reviewed September 2026. This page is educational, not medical advice.
Prebiotics
Prebiotic ingredients are typically fermentable compounds that feed selected microbes. FOS is one example used in supplements. Because fermentation produces metabolites and gas, tolerance matters.
Probiotics
Probiotic effects depend on the organism—often down to the strain. A generic “probiotic blend” claim provides less evidence than a label that identifies strains, dose and viability clearly.
Can they be combined?
Yes. Products combining a probiotic and a substrate intended to support microorganisms are often called synbiotics. Combination alone does not guarantee that the specific pairing has been clinically studied.