Probiotics get all the attention, but prebiotics are just as important — and the two are easy to confuse. Here is the plain-language difference, and how they work together.
The simple difference
Probiotics are live beneficial bacteria. Prebiotics are the fibers those bacteria feed on. Put simply, probiotics are the seeds and prebiotics are the fertilizer. A product that combines both is sometimes called a “synbiotic.”
Where prebiotics come from
Common prebiotic fibers include inulin, fructooligosaccharides (FOS) and galactooligosaccharides (GOS). You will find them naturally in foods such as onions, garlic, leeks, asparagus, bananas and oats, as well as in supplements.
What the research says
Feeding beneficial gut bacteria is a reasonable, well-supported idea, though specific health claims should be read cautiously. As with probiotics, effects depend on the person and the amount. The NCCIH overview of probiotics is a good, neutral starting point.
How to add them
Food first is the easiest approach. If you use a supplement, start with a small dose — prebiotic fibers can cause gas and bloating when introduced too quickly.
Prebiotic Fiber (e.g. inulin/FOS — NOW, Garden of Life)
- Common forms are inulin, FOS and GOS
- Start with a small dose to avoid gas and bloating
- Pairs naturally with a probiotic (together called a synbiotic)
Inexpensive · widely available
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