Prebiotics are a specific group of fibres (or sometimes other substances) that your own body does not digest, but certain gut bacteria such as Bifidobacterium and Lactobacillus do.

Well-known prebiotics

• Inulin (from chicory, garlic, onion, asparagus, leek)
• Fructo-oligosaccharides (FOS) (from fruit, pulses, onion)
• Galacto-oligosaccharides (GOS) (from milk, pulses)
• Resistant starch (from cooked and cooled potatoes, bananas, pulses)
• Beta-glucan (from oats, barley, mushrooms)

If you want to increase your fibre intake, a fibre supplement (for example inulin powder or psyllium) can be an addition to your diet. Start gradually: a sudden large amount of fibre can cause wind. Drink enough with it.

3. Probiotics — live micro-organisms

Probiotics are live micro-organisms. Well-known groups:

• Lactobacillus — one of the best-known families, also used in yoghurt and fermented vegetables.
• Bifidobacterium — found mainly in the large intestine.
• Saccharomyces boulardii — a yeast (not a bacterium).

No health claims are authorised for probiotics. In practice this means products are described neutrally and you choose on the basis of strain, dose (expressed in CFU, colony-forming units) and composition. If you take medicines, such as antibiotics, or have persistent bowel complaints, consult your doctor or pharmacist first.

Postbiotics

These are substances formed when gut bacteria ferment fibre, such as short-chain fatty acids, peptides and cell-wall fragments. So postbiotics are not live bacteria. They are still relatively new in supplements.

Synbiotics

A combination of probiotics and prebiotics in one product. Practical if you want to use both.

Which do you choose — fibre, prebiotics or probiotics?

Start with the basics: food

For most people, eating more fibre (vegetables, fruit, pulses, wholegrains) and adding fermented foods (yoghurt, kefir, sauerkraut) is a logical first step.

Fibre or prebiotic supplement

If you find it hard to get enough fibre from food, a fibre or prebiotic supplement (such as inulin, FOS, GOS or psyllium) can be an addition.

Probiotic supplement

Some people also choose a probiotic supplement. No health claims are authorised for probiotics; choose on the basis of strains, dose and product information and follow the recommended daily dose on the label.

Synbiotics: for convenience

If you want pro- and prebiotics in one product, a synbiotic product is practical. Check the composition.

Fibre, prebiotics, probiotics, postbiotics and synbiotics are different categories relating to the gut flora. The foundation is your diet: varied, fibre-rich and with fermented foods. Supplements can be an addition to that.

Disclaimer: This article is for information only and does not replace medical advice. A food supplement is not a substitute for a varied, balanced diet and a healthy lifestyle. If in doubt or if you take medication, consult a doctor or pharmacist. Do not exceed the recommended daily dose. Keep out of the reach of young children.