Prebiotic Foods List: What They Are and Where to Find Them

Prebiotics are, in the words of the 2017 ISAPP expert consensus, “a substrate that is selectively utilized by host microorganisms conferring a health benefit”. The best established are inulin-type fructans (inulin and fructooligosaccharides, FOS) and galactooligosaccharides (GOS). The richest prebiotic foods are chicory root and Jerusalem artichoke (roughly 15-20% inulin by fresh weight), followed by garlic, onions, leeks, artichokes, wheat, rye, bananas, oats and legumes such as kidney beans and split peas, while green bananas and cooked-then-cooled potatoes supply resistant starch.

This guide is for you if you keep seeing “prebiotic” on yogurt pots and supplement tubs and want to know what it means and which foods actually contain prebiotics. For the bigger picture of eating for your gut (fibre targets, fermented foods, plant variety), read our guide to gut health foods. Here we stay with prebiotics: the definition, the main types, a food table with the numbers we could verify, and who should go slowly.

What are prebiotics, exactly?

In 2016 an expert panel of the International Scientific Association for Probiotics and Prebiotics (ISAPP), led by Glenn Gibson of the University of Reading, met to update the definition. Their consensus, published in Nature Reviews Gastroenterology & Hepatology in 2017, defines a prebiotic as “a substrate that is selectively utilized by host microorganisms conferring a health benefit”.

Each part of that sentence does work:

• A substrate: something microbes can use as food.
• Selectively utilized: it feeds particular beneficial microbes, not every microbe in the gut equally.
• Conferring a health benefit: there must be documented benefit, not only a change in bacterial counts.

The 2017 statement also widened the idea: a prebiotic no longer has to be a carbohydrate, and it can act at body sites beyond the gut. The core stayed: the effect runs through microbes, and the benefit must be shown.

What is the difference between fibre and prebiotics?

ISAPP is clear that the two are not the same thing. Fibre is a broad nutritional category: the plant carbohydrates your own enzymes cannot digest. Plenty of fibre is fermented by a wide mix of gut microbes, which is useful, but that is not the same as selective use with a proven benefit. So “high in fibre” on a label does not mean “prebiotic”, and a prebiotic ingredient does not replace the fibre you get from beans, vegetables and whole grains.

What types of prebiotics are there?

Inulin and fructooligosaccharides (FOS)

ISAPP’s consumer guidance names FOS and GOS as the most widely accepted prebiotics, and treats inulin as a type of FOS. These fructans are chains of fructose that pass undigested into the colon. They are the reason chicory root is used to make commercial inulin.

Galactooligosaccharides (GOS)

GOS are short chains built on galactose. On labels you may see them as GOS or TOS (trans-GOS). In everyday food, Monash University lists legumes as the main source, with red kidney beans, split peas and baked beans particularly high.

Resistant starch

Resistant starch escapes digestion in the small intestine and is fermented in the colon. It is not on ISAPP’s short list of accepted prebiotics, but it is often discussed alongside them because microbes ferment it. A University of Florida extension guide describes the main forms: starch trapped in whole grains and seeds, naturally resistant starch in raw potatoes and green bananas, and “retrograded” starch that forms when cooked potatoes, rice or bread are cooled.

Candidate prebiotics

ISAPP lists several candidates that still need more evidence, including polydextrose, soybean oligosaccharides, isomalto-, gluco- and xylo-oligosaccharides, and some sugar alcohols such as lactitol, sorbitol and maltitol.

Prebiotic foods list: which foods contain the most?

Standard food tables rarely list prebiotics, so the table gives figures only where we could verify them.

Food	Main prebiotic type	Verified amount
Chicory root	Inulin (fructans)	15.2-20.5% inulin (root)
Jerusalem artichoke	Inulin (fructans)	17-20.5% inulin, fresh weight
Globe artichoke	Inulin (fructans)	Rich source (root 30.6-36.7% of dry matter)
Garlic, onion, leek, spring onion	Fructans	Rich source, not quantified here
Wheat, rye (wholemeal and rye bread)	Fructans	Rich source, not quantified here
Asparagus, banana, oats, soybean	Inulin-type fructans	Natural source, not quantified here
Red kidney beans, split peas, baked beans	GOS	Rich source, not quantified here
Green bananas, unripe plantains	Resistant starch	Up to 50% of dry weight
Boiled potatoes, chilled	Resistant starch	Rises from about 3.3% to 5.2% after cold storage
Cooked white rice, cooled and reheated	Resistant starch	About 2.5 times that of freshly cooked rice
Canned black beans	Resistant starch	About 2 g per 100 g

Sources: inulin values from Costabile et al., British Journal of Nutrition 2010 (chicory value citing Van Loo et al. 1995); fructan and GOS foods from Monash University FODMAP and the ISAPP consumer guidelines; resistant starch values from University of Florida IFAS Extension, FS478.

Chicory root and Jerusalem artichoke are in a league of their own, while leeks, onions and garlic carry the everyday load in European cooking.

How much prebiotic fibre do you need per day?

There is no official daily target for prebiotics. ISAPP’s consumer guide states that 5-8 g a day of FOS or GOS has a prebiotic effect in adults, and it adds an honest note: getting that much from natural sources takes a large quantity of food.

A quick calculation: at 17-20.5% inulin, 5 g of inulin is in roughly 25-30 g of raw Jerusalem artichoke, and 8 g in about 40-50 g. For onions or bananas you would need far more. That is why trials use powders, and why eating for prebiotics is about regular small amounts, not a precise number.

Are prebiotics good for gut health?

The definition itself requires a documented health benefit, so a true prebiotic has evidence behind it by design. Most of that evidence comes from set doses of FOS, inulin or GOS, not from people eating more leeks. ISAPP also warns that many ingredients marketed as prebiotics have not been shown to be used selectively by microbes or to provide a health benefit.

So eat prebiotic foods for everything else they bring too, and treat “prebiotic” on a label with the same scepticism as any other marketing word.

Do you need a prebiotic supplement or a probiotic with prebiotic?

Most people do not. If you buy one, ISAPP suggests looking for named ingredients on the label: FOS, inulin, GOS or TOS. A probiotic with prebiotic is only as useful as the evidence for that exact combination and dose. For digestive symptoms, start with food, introduced slowly; our article on natural remedies for digestion covers what else has evidence.

What does Ayurveda say about prebiotic foods?

Ayurveda has no word for prebiotics, but it has a lot to say about the foods on this list. The traditional focus is agni, your digestive fire: a food is only as good as your ability to digest it. Onion and garlic are considered heating and pungent, and in many Ayurvedic and yogic traditions they are used carefully or avoided by people who want a calm mind. Beans and lentils are seen as drying and gas-forming, which is why classic cooking pairs them with digestive spices such as cumin, ginger and a pinch of asafoetida (hing), and cooks them until very soft.

The traditional advice fits modern caution: cook the gassier foods well, spice them, and eat amounts your digestion handles. A pot of kitchari made with split mung beans is the classic Ayurvedic way to eat legumes gently. This is a description of tradition, not scientific evidence.

How can you eat more prebiotic foods? A cooled potato and white bean salad

Three prebiotic sources in one bowl: resistant starch from chilled potatoes, legumes and leek. It keeps for two days in the fridge.

Ingredients (2 servings)

• 400 g waxy potatoes, unpeeled
• 200 g cooked white beans (see how to cook white beans), rinsed if canned
• 1 small leek, white and light green part, very thinly sliced
• 1 small handful of fresh dill, chopped
• 2 tablespoons extra virgin olive oil
• 1 tablespoon apple cider vinegar
• 1 teaspoon mustard
• Salt and black pepper to taste

Steps

1. Boil the potatoes in salted water until a knife slides in easily, about 20 minutes.
2. Drain, let them cool, then refrigerate for at least 4 hours or overnight.
3. Put the sliced leek in a sieve and pour hot water over it to soften the bite.
4. Whisk the olive oil, vinegar, mustard, salt and pepper.
5. Cut the cold potatoes into chunks, add the beans, leek and dill, pour over the dressing and toss.

Our 7-day anti-inflammatory meal plan uses many of the same foods, and ground flaxseed is an easy fibre add-on for breakfast.

Who should be careful with prebiotic foods?

• Anyone adding them fast. Bloating and mild flatulence are a well-known side effect of inulin-type fructans. In one controlled study, 10 g a day of a long-chain inulin raised reported bloating compared with placebo, although the average rating stayed mild. Add one new food every few days.
• People with irritable bowel syndrome (IBS). Fructans and GOS belong to the FODMAPs, sugars that are poorly absorbed and are fermented by gut bacteria, producing gas. Monash University explains that the extra gas and water stretch the bowel wall, which a sensitive gut feels as pain. Many prebiotic foods (garlic, onion, leek, artichoke, wheat, kidney beans) are high-FODMAP.
• Anyone thinking of a low-FODMAP diet. Monash describes it as a 2-6 week period of high restriction followed by gradual reintroduction, intended for people with medically diagnosed IBS and best done with a dietitian. It is a diagnostic tool, not a forever diet.

Related reading: gut health foods, kitchari recipe, flaxseed benefits.

FAQ

What is the difference between prebiotics and probiotics?

Prebiotics are food for microbes: substances such as inulin, FOS and GOS that beneficial gut microbes use selectively. Probiotics are live microorganisms themselves, found in some supplements and fermented foods. One feeds, the other is the microbe.

What is the best prebiotic food?

By verified inulin content, chicory root and Jerusalem artichoke lead, at roughly 15-20% of fresh weight. For everyday eating, onions, leeks, garlic, oats and legumes are easier to eat often, and regular small amounts matter more than one big dose.

Is a banana a prebiotic food?

Yes, in two ways. Bananas contain inulin-type fructans, and green bananas are rich in resistant starch, up to half of their dry weight according to University of Florida extension data. The greener the banana, the more resistant starch it carries.

Are prebiotic foods low FODMAP?

Mostly not. Fructans and GOS are themselves FODMAPs, so garlic, onions, leeks, wheat and many beans are high-FODMAP. If you have IBS, work with a dietitian to find which ones and how much you tolerate, rather than cutting them all for good.

Sources

1. Gibson GR, Hutkins R, Sanders ME, Prescott SL, Reimer RA, Salminen SJ, Scott K, Stanton C, Swanson KS, Cani PD, Verbeke K, Reid G. Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics. Nature Reviews Gastroenterology & Hepatology, 2017. doi:10.1038/nrgastro.2017.75. cora.ucc.ie/handle/10468/4142
2. International Scientific Association for Probiotics and Prebiotics (ISAPP). Prebiotics: consumer guidelines. ISAPP, 2019. isappscience.org
3. Costabile A, Kolida S, Klinder A, Gietl E, Bäuerlein M, Frohberg C, Landschütze V, Gibson GR. A double-blind, placebo-controlled, cross-over study to establish the bifidogenic effect of a very-long-chain inulin extracted from globe artichoke in healthy human subjects. British Journal of Nutrition, 2010;104:1007-1017. doi:10.1017/S0007114510001571. cambridge.org
4. Pereira-Mendes RM, Matheu AI, Vigre IM, Andrade J, Andrade Laborde JE. Resistant Starch: What It Is, Why It Matters, and How to Add More to Your Plate. University of Florida IFAS Extension, FS478. ask.ifas.ufl.edu/publication/FS478
5. Monash University. About FODMAPs and IBS. Monash FODMAP. monashfodmap.com/about-fodmap-and-ibs
6. Monash University. High and low FODMAP foods. Monash FODMAP. monashfodmap.com

This article is for information only and is not medical advice. If you have a health condition, are pregnant or take medication, talk to your doctor or pharmacist before changing your diet or starting a supplement.