What Actually Counts as a "Probiotic" or "Prebiotic"

What Happened

The field's expert consensus body (ISAPP) defines a probiotic as live microorganisms that confer a health benefit when administered in adequate amounts, and a prebiotic as a substrate selectively used by host microorganisms to confer a benefit. These are strain- and substance-specific claims — benefits shown for one strain don't automatically apply to others.

Informational content based on peer-reviewed research and major health authority guidelines — not medical advice.

Why It Matters

An expert consensus body formally defining these terms exists precisely because 'probiotic' and 'prebiotic' had become marketing words applied loosely to almost anything fermented or fibrous.

A benefit shown for one strain doesn't automatically belong to every strain wearing the same label.

FET's Takeaway

The strain-specificity point is the one worth internalizing for any product claim: a health benefit shown for one probiotic strain in one clinical context doesn't transfer to a different strain just because both are labeled 'probiotic.'