Guide · Microbiome
Prebiotics, probiotics, and postbiotics—without the word soup
Three similar-sounding terms describe different things. Here is the distinction that actually matters when you shop or plan a meal.
The “biotic” vocabulary has expanded faster than most labels explain it. The terms are related, but they are not interchangeable.
Prebiotics
Prebiotics are substrates selectively used by microorganisms in a way that provides a health benefit. In everyday language, they are compounds that certain gut microbes can use. Many—though not all—are fibers.
Probiotics
Probiotics are live microorganisms that confer a health benefit when administered in adequate amounts. The strain and studied use matter. “Contains probiotics” is not enough information to predict an outcome.
Postbiotics
Postbiotics are preparations of inanimate microorganisms and/or their components that provide a health benefit. They are not simply any by-product produced during fermentation.
What to do with those definitions
For food, focus first on a varied eating pattern that you can tolerate and maintain. For supplements, look for specificity: named strains, an amount through the end of shelf life, storage instructions, and a reason the formula matches your goal.
A longer ingredient list is not automatically a better one.