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Prebiotic fibre (inulin / FOS / GOS)

Soluble fermentable fibres that selectively feed bifidobacteria, the EFSA-recognised bifidogenic effect.

Why

Inulin, fructooligosaccharides (FOS) and galactooligosaccharides (GOS) are non-digestible fermentable carbohydrates that pass undigested into the colon, where they are selectively fermented by bifidobacteria and lactobacilli, the so-called bifidogenic effect. EFSA has issued opinions accepting chicory inulin's effect on bowel function and the general bifidogenic effect of FOS and GOS, though authorised health claims under Reg 432/2012 are narrower. Effects include increased stool frequency in mild constipation, improved mineral absorption, and modulation of postprandial glucose.

How it works

Resistant to upper-GI digestion; fermented by colonic Bifidobacterium and Lactobacillus species into short-chain fatty acids (acetate, propionate, butyrate). SCFA acidification suppresses pathogens, supports colonocyte energy supply, and modulates gut-derived satiety signalling (PYY, GLP-1).

Expected onset · Bifidobacteria changes within days; stool form changes within 1–2 weeks

How to take

Dosage

Start at 3–5 g/day and titrate upwards as tolerated. Maintenance: 5–15 g/day. Chicory inulin's EFSA-recognised bowel-function effect uses ≥12 g/day.

Timing

Once or twice daily, with or away from meals

On the label

'Chicory inulin', 'FOS', 'GOS', 'oligofructose' with stated grams per dose. Larch arabinogalactan and partially hydrolysed guar gum are alternative gentler prebiotics.

Ideal for

Adults with mild constipation, low microbiota diversity, or seeking to support general gut microbiota health alongside dietary fibre.

Safety

GI gas, bloating and abdominal discomfort are common, especially when starting. Titrate slowly. Avoid or restrict in IBS with FODMAP-sensitivity, SIBO, or active inflammatory bowel disease flare (high-FODMAP). Pregnancy and breastfeeding: dietary doses safe.

Evidence

At a glance

EFSA NDA Panel 2015 accepted a cause-and-effect relationship between chicory inulin (≥12 g/day) and maintenance of normal defaecation through increased stool frequency. Multiple meta-analyses confirm increases in bifidobacteria abundance at 5–20 g/day across FOS, GOS and inulin. Strong mechanistic base; modest clinical-symptom effects in healthy adults.

Where to get it

Shop Prebiotic fibre (inulin / FOS / GOS) on Amazon

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