Prebiotic foods: a list with real numbers, and what a prebiotic soda adds
What a prebiotic is, which foods contain inulin and how much, how Olipop, Poppi and Pepsi prebiotic cola compare with lentils and apples, and who should go slowly.
Short answer
A prebiotic is a substrate that gut microbes selectively use and that gives you a documented health benefit. Garlic, leeks, onions, asparagus, Jerusalem artichokes, wheat and chicory are the classic inulin foods, and legumes bring a different group called GOS. A prebiotic soda adds 2 to 9 grams of added fiber per can, which is real but modest next to a day of whole foods, and chicory inulin can bother people with IBS.
Key takeaways
- The accepted definition of a prebiotic requires two things: selective use by gut microbes and a documented health benefit. "Contains fiber" alone does not qualify.
- Typical intake of inulin and oligofructose from food is about 1 to 10 g a day (a 1995 review of Western diets). In a survey of over 15,000 Americans it averaged 2.6 g inulin and 2.5 g oligofructose, mostly from wheat (about 70%) and onions (about 25%).
- Standard fiber tables do not capture inulin. USDA lists Jerusalem artichoke at 1.6 g of fiber per 100 g, while a 2025 review of plant sources reports 17 to 20.5 g.
- Prebiotic sodas range from about 2 to 3 g of fiber (Poppi) to 6 to 9 g (Olipop). A 9 g can matches roughly 115 g of cooked lentils.
- Inulin, chicory root and similar additives can cause gas and bloating in people with IBS, as Monash University warns.
Open a food-composition table and look up Jerusalem artichoke. You will find 1.6 grams of fiber per 100 grams.4 Open an analytical survey of what is actually in the tuber and you will find inulin alone at 17 to 20.5 grams per 100 grams.5 The gap is a methods problem: classic dietary fiber analysis, which food tables rely on, does not measure inulin.3 That mismatch is why “prebiotic foods” lists are so often vague, and why a can of soda can claim a number a vegetable never gets credit for.
What counts as a prebiotic
The expert definition, from a 2017 panel of the International Scientific Association for Probiotics and Prebiotics, is “a substrate that is selectively utilized by host microorganisms conferring a health benefit”. The panel kept two requirements: the microbes must use it selectively, and the benefit has to be documented.1 So a prebiotic is not any fiber. Plenty of fibers feed gut bacteria. Fewer have documented benefits tied to a selective effect.
In practice, the foods people mean fall into a few groups. The German consumer organization lists inulin and oligofructose in chicory, artichoke, salsify, the onion family (leek, garlic, onion), asparagus and cabbage, GOS in legumes, pectin in apples, pears, berries and citrus, and resistant starch in cooled pasta, potatoes and rice, and bananas.10
The numbers: inulin versus total fiber
| Food (per 100 g, raw unless noted) | Inulin, g (survey range) | Total fiber, g (USDA) |
|---|---|---|
| Chicory root | 15 to 20 | 1.5 |
| Jerusalem artichoke | 17 to 20.5 | 1.6 |
| Garlic | 9 to 16 | 2.1 |
| Leek | 3 to 10 | 1.8 |
| Onion | 3.09 to 4.96 | 1.7 |
| Asparagus | 2 to 3 | 2.1 |
| Wheat, whole grain (soft white) | 1.5 to 2.3 | 12.7 |
| Banana (ripe) | 0.6 to 1.1 | 2.6 |
| Lentils, cooked | GOS source, not inulin | 7.9 |
| Chickpeas, cooked | GOS source, not inulin | 7.6 |
| Apple, with skin | pectin source | 2.4 |
Inulin ranges are g per 100 g fresh weight as tabulated in a 2025 review of plant sources.5 Fiber values are USDA FoodData Central SR Legacy entries.4 Inulin varies with variety, ripeness and storage, so treat the ranges as ranges.
The foods with the most inulin are not the foods with the most fiber: legumes win on total fiber, and the strongest prebiotic foods barely register on it. A typical day also looks small next to the big numbers. A USDA survey of more than 15,000 Americans put average intake at 2.6 g of inulin and 2.5 g of oligofructose, with wheat providing about 70% and onions about 25%.2 A classic review estimates 1 to 10 g of inulin and oligofructose a day in Western diets, depending on age, sex and region, and that is the range this site uses.3 German consumer advice quotes a slightly higher 3 to 11 g, but for inulin and other oligosaccharides together, which is a wider group.11
Prebiotic soda, in grams
Now the can. A 12 fl oz can of Olipop contains 6 to 9 grams of fiber, depending on the product line.8 Its blend, per Fortune, includes cassava root fiber, chicory root inulin and Jerusalem artichoke inulin, plus plant extracts. Poppi contains about 2 to 3 grams, from agave inulin, and its label says it is “not a significant source of fiber”. Coca-Cola’s Simply Pop is listed at 6 grams from soluble corn fiber.7 Pepsi’s own product page lists 3 grams of dietary fiber per 12 fl oz can (12% of the Daily Value), and PepsiCo names soluble corn fiber as the source.9
| Product | Fiber per can | Compare with (USDA fiber) |
|---|---|---|
| Poppi | 2 to 3 g | about 100 g of apple (2.4 g) or banana (2.6 g) |
| Pepsi Prebiotic Cola | 3 g | about 115 g of banana |
| Simply Pop | 6 g | about 75 g of cooked lentils |
| Olipop | 6 to 9 g | up to about 115 g of cooked lentils |
Comparisons are straight division of the can’s fiber by USDA’s grams per 100 g.4
So is it worthless? No. If a soda replaces a sugary soda, you take in some fiber and less sugar, and 9 grams is close to a third of a recommended daily intake of roughly 30 grams.7 What the marketing leaves out: the fiber is extracted, so you do not get the vitamins, minerals and the mix of fibers in a lentil or an apple, as a dietitian quoted by Fortune points out. And the very ingredient that makes it “prebiotic” is the one more likely to cause trouble.
Who should go slowly
Prebiotic fibers feed bacteria by being fermented, and that makes gas. Monash University, the group behind the low-FODMAP diet, notes that ingredients such as inulin, chicory root, Jerusalem artichoke powder, FOS and GOS added to boost the prebiotic content of products can cause gas, bloating and abdominal distension in some people with IBS.6 The German consumer organization says sensitive people may react to under 10 grams a day, while most people tolerate up to 30 grams spread through the day, and that it can be worse when the fiber arrives in a drink.10
Sensitive gut? Start small
If you have IBS or a gut that reacts to onions and garlic, add one prebiotic food at a time and give it a few days. Persistent bloating, pain, blood in the stool or a change in bowel habits lasting more than a few weeks is a reason to see a doctor, not to try another drink.
What to do with all this
Put the cheap, boring prebiotics on the plate: onion and garlic in the pan, leeks in soup, a handful of oats, a can of chickpeas in a salad. They also do the job a soda cannot, which is to add a different plant to your week. And if you like a prebiotic soda, treat it as a soda that happens to have some fiber, which is what the grams say it is.
Frequently asked questions
What is a prebiotic?
A prebiotic is a substrate that is selectively used by host microorganisms and gives a health benefit. The 2017 expert definition keeps the requirement that the benefit must be documented, so not every fiber counts.
What are the best prebiotic foods?
The classic inulin sources are chicory root, Jerusalem artichoke, garlic, leeks, onions, asparagus and wheat. Legumes are a source of GOS, and cooked and cooled rice, pasta and potatoes give resistant starch.
Is prebiotic soda healthy?
It can be a reasonable swap for a sugary soda and adds some fiber, but the amount is small next to whole foods, the fiber is isolated rather than a whole plant, and some of the ingredients, such as chicory inulin, can trigger gas and bloating.
How much inulin do I need per day?
There is no official requirement. Typical dietary intake of inulin and oligofructose is about 1 to 10 g a day. A German consumer organization notes that most people tolerate up to 30 g spread through the day, while sensitive people can react to less than 10 g.
Can prebiotics cause bloating?
Yes. Prebiotic fibers are fermented by gut bacteria, which makes gas, and in some people with IBS that causes bloating and abdominal distension. Increase the amount slowly.
Sources
Figures, study results and official recommendations in this article come from these sources. Everyday cooking and shopping tips are our own judgment.
- Gibson GR, et al. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics. Nature Reviews Gastroenterology & Hepatology. 2017;14(8):491-502. doi.org
- Moshfegh AJ, Friday JE, Goldman JP, Ahuja JK. Presence of inulin and oligofructose in the diets of Americans. Journal of Nutrition. 1999;129(7 Suppl):1407S-1411S. pubmed.ncbi.nlm.nih.gov
- Van Loo J, et al. On the presence of inulin and oligofructose as natural ingredients in the western diet. Critical Reviews in Food Science and Nutrition. 1995;35(6):525-552. pubmed.ncbi.nlm.nih.gov
- USDA FoodData Central, SR Legacy: Jerusalem-artichokes, raw (169236); garlic, raw (169230); leeks, raw (169246); onions, raw (170000); asparagus, raw (168389); bananas, raw (173944); apples, raw, with skin (171688); chicory roots, raw (169993); wheat, soft white (169720); chickpeas, cooked (173757); lentils, cooked (172421). fdc.nal.usda.gov
- Canazza E, Grauso M, Mihaylova D, Lante A. Techno-Functional Properties and Applications of Inulin in Food Systems. Gels. 2025;11(10):829. Table 1, inulin in g per 100 g fresh weight (secondary summary of the analytical surveys). doi.org
- Monash FODMAP. Label reading and FODMAPs. monashfodmap.com
- Fortune. Are prebiotic sodas like Simply Pop, Olipop, and Poppi healthy? fortune.com
- OLIPOP. Understanding the OLIPOP nutrition label (6 to 9 g fiber per 12 fl oz can). drinkolipop.com
- Pepsi. Pepsi Prebiotic Cola, official product page (Nutrition Facts: 12 fl oz, dietary fiber 3 g, 12% DV). pepsi.com
- Verbraucherzentrale. Lebensmittel mit präbiotischen Ballaststoffen: Wirkung nicht belegt (in German, May 2026). verbraucherzentrale.de
- Verbraucherzentrale Bayern. Wie viel Inulin ist gesund? (in German; as of January 20, 2022: 3 to 11 g a day of inulin and other oligosaccharides). verbraucherzentrale.bayern
This article is general information, not medical advice. If you have ongoing digestive symptoms, a diagnosed condition like IBS or IBD, or you are pregnant, talk to a doctor or registered dietitian before changing your diet.
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