What Are Prebiotics?
Prebiotics are food components — mainly fibres and oligosaccharides — that humans cannot digest but which serve as food for beneficial bacteria in the gut. The concept was introduced by Gibson and Roberfroid in 1995. A prebiotic must meet three criteria: it must resist digestion in the small intestine, be fermented by specific gut microorganisms, and selectively stimulate the growth or activity of beneficial bacteria (Gibson et al., 2017).
Inulin — The Most Recognised Prebiotic
Inulin is a polymer of fructose chains found naturally in chicory, artichoke, Jerusalem artichoke, and onions. As a supplement it comes in different chain lengths:
- Short-chain inulin (FOS) — ferments quickly, acts in the upper colon
- Long-chain inulin — ferments more slowly and deeper in the large intestine
- Inulin-FOS blend — provides broader microbiome support
ICONFIT Superfoods Inulin Powder 250g (about €7.40 at the time of writing) is a pure chicory-derived inulin powder that can easily be added to drinks or yoghurt. It has a mild taste and dissolves well, making it ideal for daily use. For more detail, see which inulin form is the best choice.
Clinical trials have confirmed that consuming 5–10 g of inulin daily significantly increases Bifidobacterium and Lactobacillus populations in the gut (Roberfroid et al., 2010).
FOS — Fructo-Oligosaccharides
FOS (fructo-oligosaccharides), also called short-chain inulin, consists of chains of 2–8 fructose units. They occur naturally in bananas, garlic, onions, and asparagus.
Main effects of FOS:
- Increases Bifidobacterium populations
- Lowers colon pH, inhibiting pathogen growth
- Improves absorption of minerals, especially calcium and magnesium
- Shortens gut transit time
The recommended FOS dose is 5–10 g per day, but start at 2–3 g to allow the gut to adapt — increasing too quickly can cause bloating and gas.
GOS — Galacto-Oligosaccharides
GOS (galacto-oligosaccharides) occur naturally in breast milk and are critical for shaping the infant gut microbiome. In adult supplements GOS is most commonly derived from lactose via fermentation.
GOS versus FOS:
| Property | FOS | GOS |
|---|---|---|
| Source | Chicory root, onions | Milk, lactose |
| Fermentation speed | Fast | Moderate |
| Primary beneficiaries | Bifidobacterium | Bifidobacterium, Lactobacillus |
| Infant formula use | Less common | Widely used |
Research shows that GOS combined with Lactobacillus rhamnosus reduced watery diarrhoea in infants and protected against Clostridium difficile infection (Vulevic et al., 2008).
How to Use Prebiotics Correctly
Dosing
- Start low: 2–3 g per day in the first week
- Gradually increase to 5–10 g per day
- Split the dose across meals to reduce digestive side effects
With Probiotics
Prebiotics and probiotics complement each other beautifully. Adding prebiotics to a probiotic course is the synbiotic approach — proven more effective than either alone (Bindels et al., 2015). Try combining ICONFIT Superfoods Inulin Powder 250g with SELF Probiotic Lactospore 60 caps to support both live culture establishment and long-term survival. Many people also combine prebiotics with a regular protein supplement after training — see the protein category at maxfit.ee. For more on timing, see When to take probiotics: timing that actually matters.
Food-Based Sources
- Chicory root — highest inulin content (40–48 g/100 g)
- Jerusalem artichoke — 16–20 g/100 g
- Garlic — 9–16 g/100 g
- Onion — 2–6 g/100 g
- Banana — 0.3–0.7 g/100 g (unripe bananas contain more)
See also natural food sources of inulin and the vitamin complexes category if you are looking for broader digestive support. You can find prebiotic supplements at maxfit.ee's digestive enzymes and probiotics category.
FAQ
What is the difference between a prebiotic and a probiotic?
Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host. Prebiotics, by contrast, are non-digestible compounds that feed and stimulate the growth of existing beneficial bacteria — essentially fertiliser for the gut garden.
Are prebiotics suitable for people with IBS?
This is individual. Some people with IBS react poorly to high-FODMAP prebiotics like FOS. In that case, start with low-dose GOS (1–2 g), which is often better tolerated. Consult a dietitian if symptoms worsen.
Can inulin be used in baking?
Yes, inulin is heat-stable and works well as a fat and sugar replacer in baked goods. High temperatures do slightly reduce its prebiotic activity, though.
References
- Gibson, G. R. et al. (2017). Expert consensus document: The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term prebiotic. Nature Reviews Gastroenterology & Hepatology, 14(8), 491–502. https://pubmed.ncbi.nlm.nih.gov/28611480/
- Roberfroid, M. et al. (2010). Prebiotic effects: metabolic and health benefits. British Journal of Nutrition, 104(Suppl 2), S1–S63.
- Vulevic, J. et al. (2008). Modulation of the fecal microflora profile and immune function by a novel trans-galactooligosaccharide mixture in healthy elderly volunteers. American Journal of Clinical Nutrition, 88(5), 1438–1446. https://pubmed.ncbi.nlm.nih.gov/18996881/
- Bindels, L. B. et al. (2015). Towards a more comprehensive concept for prebiotics. Nature Reviews Gastroenterology & Hepatology, 12(5), 303–310. https://pubmed.ncbi.nlm.nih.gov/25824997/
