Why combine probiotics and prebiotics?
The digestive tract is home to trillions of microorganisms — including bacteria that play an essential role in digestion, immunity, and overall wellbeing. Probiotics are live beneficial bacteria obtained from food or supplements (Hill et al., 2014). Prebiotics are fibres that feed these beneficial bacteria (Gibson et al., 2017). Together they form a synbiotic combination (Swanson et al., 2020) — probiotics add beneficial bacteria, and prebiotics ensure they have food.
How probiotics work
Probiotics are live microorganisms that help maintain the balance of gut microbes. Currently, EFSA has not approved specific health claims for probiotics, but they are intensively studied.
Effects of probiotics:
- Support gut microbiome diversity
- Help restore microbiome balance after antibiotic use
- Research points to positive effects on digestion
- Most studied strains: Lactobacillus and Bifidobacterium families
Probiotic sources:
- Fermented foods: yoghurt, kefir, sauerkraut, kimchi, miso
- Supplements: capsules, powders (CFU — colony forming units count)
How prebiotics work
Prebiotics are indigestible fibres that feed beneficial gut bacteria. They pass through the stomach and small intestine undigested, reaching the large intestine where beneficial bacteria use them.
Prebiotic fibres:
- Inulin — found in onions, garlic, artichoke, chicory root
- Fructo-oligosaccharides (FOS) — bananas, onions, asparagus
- Galacto-oligosaccharides (GOS) — milk, beans
- Resistant starch — cooled potato, cooled rice, green bananas
- Psyllium — well known as a fibre supplement
EFSA has approved general claims for fibre but not specifically for prebiotics:
- Fibre contributes to normal bowel function
The synergy effect
The interaction of probiotics and prebiotics — synbiotics — is logical and easy to understand:
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Nourishment and growth — prebiotics provide substrate (food) for probiotics. This helps probiotics survive and multiply in the digestive tract.
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Better colonisation — when probiotics arrive in the gut via supplementation, the presence of prebiotics gives them a better chance of establishing themselves.
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Short-chain fatty acids — when bacteria ferment prebiotic fibres, short-chain fatty acids (butyrate, propionate, acetate) are produced. These support gut barrier health and serve as an energy source for colon cells.
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Diversity — prebiotics feed not only supplement-derived probiotics but also existing beneficial bacteria. This supports overall microbiome diversity.
Recommended protocol
Probiotics:
- Dose: 10–50 billion CFU daily (start with a lower dose)
- Diversity: choose a product containing at least 3–5 different strains
- Preferred strains: Lactobacillus acidophilus, L. rhamnosus, Bifidobacterium lactis, B. longum
- Refrigerate if indicated on the package
- Take in the morning before or with food
Prebiotics:
- From food: eat a diverse range of fibre-rich foods — onions, garlic, bananas, oats, flaxseeds, beans
- As a supplement: 5–10 g of prebiotic fibres daily (inulin, FOS, psyllium)
- Important: increase fibre gradually — too rapid an increase can cause gas and bloating
Combined approach:
- Morning: probiotic + fibre-rich breakfast (oats with flaxseeds)
- Throughout the day: varied diet with fibre-rich foods
- Drink sufficient water — fibre needs liquid
- Fermented foods (yoghurt, kefir) provide natural probiotics as an added benefit
After an antibiotic course:
- Start probiotics during the antibiotic course (but at a different time — at least 2 hours after the antibiotic)
- Continue for at least 4 weeks after the course ends
- Add prebiotic fibres to support microbiome recovery
Who benefits most
- After antibiotic courses — antibiotics destroy both harmful and beneficial bacteria
- People with digestive issues — bloating, constipation, irregular digestion
- Travellers — new environments and food can disrupt gut balance
- Stressed individuals — stress affects gut microbiome composition
- People with low-fibre diets — Western diets are often low in fibre
- Athletes — intense training can affect gut barrier function
Frequently asked questions
Are fermented foods sufficient? Fermented foods (yoghurt, kefir, kimchi) are an excellent source of natural probiotics. Supplements offer larger quantities and specific strains. Ideally, combine both.
Do probiotics permanently colonise the gut? Most probiotics do not permanently colonise the gut — they pass through and exert beneficial effects during that time. This is why regular consumption is important.
Do prebiotics cause gas? Yes, especially initially. Increase fibre gradually over 1–2 weeks so the body can adapt. Gas typically decreases over time.
Can children use probiotics? Yes, but choose a product designed for children with child-appropriate strains and lower doses. Consult a paediatrician if needed.
When can I expect results? Relief from digestive issues may be noticeable within 1–2 weeks. More significant changes in microbiome composition require 4–8 weeks of regular use.
Are probiotics and prebiotics safe? Yes, they are generally safe for healthy individuals. People with immune deficiencies should consult a doctor before using probiotics.
References
- Hill, C. et al. (2014). Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the scope and appropriate use of the term probiotic. Nature Reviews Gastroenterology & Hepatology, 11(8), 506–514.
- Gibson, G.R. et al. (2017). 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, 14(8), 491–502.
- Swanson, K.S. et al. (2020). The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of synbiotics. Nature Reviews Gastroenterology & Hepatology, 17(11), 687–701.
- Hemarajata, P. & Versalovic, J. (2013). Effects of probiotics on gut microbiota: mechanisms of intestinal immunomodulation and neuromodulation. Therapeutic Advances in Gastroenterology, 6(1), 39–51.
See also:
Disclaimer
A food supplement is not a substitute for a varied and balanced diet and a healthy lifestyle.
