The 25 Highest-Prebiotic Foods (Fibre Types Named, Grams Per Serving)

The richest whole-food source of inulin. Used industrially to extract inulin for supplements. Very high FODMAP - IBS patients must introduce in tiny amounts (1-2 g). Roasted chicory is used as a coffee substitute.

Source: Van Loo et al., Crit Rev Food Sci Nutr 1995

Tuber with the highest inulin content of commonly eaten vegetables. Causes significant gas - start with 5 g and build up over weeks. Cooking reduces inulin content slightly.

Source: Roberfroid, J Nutr 2007

One of the most concentrated prebiotic sources available as a salad green. Bitter flavour. Available in spring. Also provides beta-carotene and vitamin K.

Source: USDA FoodData Central 2023

2-3 garlic cloves provide ~2.5 g FOS. Cooking reduces FOS content. Supports Lactobacillus and Bifidobacterium growth. Also has antimicrobial properties - interestingly, it selectively feeds beneficial bacteria while inhibiting pathogens.

Source: Roberfroid et al., J Nutr 2010

Member of the allium family alongside garlic and onion. Milder flavour makes it an easy prebiotic addition to cooked dishes. Also provides kaempferol (a flavonoid with emerging anti-inflammatory evidence).

Source: Van Loo et al., Crit Rev Food Sci Nutr 1995

Cooking reduces prebiotic content significantly - raw onion is preferable for prebiotic benefit. High-FODMAP (fructans): problematic for IBS patients. Yellow onion > white > sweet onion for prebiotic content.

Source: Niness, J Nutr 1999

One of the classic prebiotic vegetables in the ISAPP literature. Steam lightly rather than boil to preserve inulin content. Compounds responsible for the characteristic post-asparagus urine odour are unrelated to prebiotic activity.

Source: Gibson & Roberfroid, J Nutr 1995

Starch in unripe bananas is largely resistant starch (RS2), which passes undigested to the colon where it is fermented by gut bacteria. As the banana ripens, RS converts to digestible sugars. Green banana flour is a supplement alternative.

Source: Topping & Clifton, Physiol Rev 2001

EFSA-approved health claim for beta-glucan and LDL cholesterol reduction (3 g/day threshold). Also feeds Bifidobacterium and Lactobacillus. Overnight oats (soaked, not cooked) preserve more of the beta-glucan than hot cooking.

Source: EFSA NDA Panel, EFSA Journal 2011; Rebello et al., J Am Coll Nutr 2015

Higher beta-glucan content per serving than oats. Reduces LDL cholesterol and post-meal blood glucose. Hulled barley > pearl barley for fibre content. A versatile grain for soups and grain bowls.

Source: Wolever et al., Am J Clin Nutr 2010

Pectin in apple skin increases Bifidobacterium and Lactobacillus in human studies. Eat unpeeled. Cooking (apple sauce) reduces pectin's prebiotic efficacy. Also provides quercetin, an anti-inflammatory polyphenol.

Source: Scheppach et al., Eur J Clin Nutr 2001

Must be ground (not whole) to release fibre and omega-3 ALA. The mucilaginous fibre forms a gel that slows digestion and feeds colonic bacteria. Also a source of lignans (phytoestrogen precursors).

Source: Dahl et al., Nutrients 2020

Soaking activates the mucilage gel. The gel-forming fibre feeds colonic bacteria and slows glucose absorption. Also an omega-3 ALA source. Less studied than inulin or beta-glucan for specific prebiotic effects.

Source: Reyes-Caudillo et al., Food Chem 2008

One of the best combined protein + prebiotic sources. GOS from lentils are well-tolerated and selectively feed Bifidobacterium. Canned lentils (rinsed) retain prebiotic benefit. Red, green, and Puy lentils are similar in fibre content.

Source: Dahl et al., Br J Nutr 2010

GOS from chickpeas is among the best-studied prebiotic fibres for Bifidobacterium. Canned chickpeas have similar fibre content to home-cooked. Hummus retains prebiotic benefit. High satiety, low glycaemic index.

Source: Halmos et al., Gastroenterology 2014

Resistant starch forms when cooked potato cools. Refrigerate overnight after cooking; reheating moderately (not fully) partially preserves the RS3. Potato starch supplements are the concentrated version. Also provides potassium.

Source: Topping & Clifton, Physiol Rev 2001

Same retrogradation mechanism as potatoes. Refrigerating overnight roughly doubles RS3 content versus freshly cooked rice. A 2015 study (Jl Chem) found cooking rice with coconut oil and refrigerating increased RS by up to 10x.

Source: Sri Lanka Journal of Chemistry 2015

Among the best studied prebiotics in European populations. Arabino-xylo-oligosaccharides (AXOS) from wheat bran selectively increase Bifidobacterium counts. Available as loose bran to add to cereals, smoothies, or baking.

Source: Damen et al., J Nutr 2012

A human trial (Ukhanova et al., Br J Nutr 2014) found pistachio consumption increased Bifidobacterium and Lactococcus counts. Polyphenols in pistachios act as prebiotics independently of fibre content.

Source: Ukhanova et al., Br J Nutr 2014

The almond skin contains the prebiotic content. Blanched almonds (skins removed) provide less prebiotic benefit. A 2014 study (Ukhanova et al.) found increased Bifidobacterium and Clostridium cluster XIV with almond consumption.

Source: Ukhanova et al., Br J Nutr 2014

Cocoa polyphenols (flavanols) are fermented by gut bacteria into compounds that increase Lactobacillus and Bifidobacterium. A 2011 AOCS trial found cocoa consumption increased Bifidobacterium and Lactobacillus while reducing Clostridium counts.

Source: Tzounis et al., Am J Clin Nutr 2011

Root vegetable popular in Japanese (gobo) and Korean cuisine. Similar inulin profile to asparagus and leek. Also contains polyphenols with antioxidant properties. Slice thinly and cook in stir-fry or soup.

Source: USDA FoodData Central 2023

Unripe plantain has more RS than ripe. Boiling or roasting green plantain retains meaningful RS content. A staple prebiotic food in Central American and West African diets. Good option for those avoiding wheat.

Source: Topping & Clifton, Physiol Rev 2001

Whole grain rye bread is one of the few baked foods with meaningful prebiotic content. Arabinoxylan from rye survives baking. Sourdough rye bread provides both prebiotic fibre and postbiotic organic acids from fermentation.

Source: Abell et al., Appl Environ Microbiol 2008

Mild anise flavour, versatile raw in salads or cooked. Contains inulin similar to other allium-adjacent vegetables. Also a traditional digestive remedy (fennel seed tea) - the inulin may partly explain digestive benefits.

Source: Van Loo et al., Crit Rev Food Sci Nutr 1995