Ingredient Repository · Ingredient

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Ingredient

Fructooligosaccharides (FOS)

A soluble prebiotic fibre that feeds good gut bacteria and helps your body absorb key minerals.

What it is

Fructooligosaccharides (FOS) are a type of soluble dietary fibre found naturally in plants like chicory root, onions, and asparagus. Your stomach cannot digest FOS, so it passes into the colon fully intact. Formulated alongside Velobiotics microencapsulated probiotics, FOS acts as the ultimate food source to nourish live probiotic cultures when they arrive in your gut.

Also known as: FOS, Prebiotic FOS, Oligofructose

Key benefits

  • Feeds beneficial Bifidobacteria and Lactobacilli, so your friendly gut microflora can thrive.
  • Boosts gut production of nourishing compounds, which nourish your gut lining.
  • Improves your body's absorption of essential minerals like calcium and magnesium.
  • Promotes soft, regular bowel movements, helping you stay comfortable every day.

Amplified by probiotics

FOS is the ideal fuel for live probiotic bacteria. When Velobiotics protected probiotics arrive in your colon, they break down FOS into nourishing compounds like butyrate (a compound that feeds your gut lining). This slightly acidifies your gut, keeping unwelcome bacteria away while helping your body absorb calcium and magnesium. Feeding your gut probiotics and FOS together gives you complete gut support.

Typical dose

2–10 g/day

The evidence

Evidence: strong

Extensive human studies show that taking FOS significantly increases friendly Bifidobacteria in the human gut. Studies also show that FOS improves calcium absorption, encourages regular bowel habits, and strengthens the gut lining (Caldaria E 2026, Int Immunopharmacol) (Bideshki MV 2026, Sci Rep) (Pretorius RA 2026, Nutr J).

  1. Caldaria E, et al. Exploratory pilot trial of a multicomponent immunonutritional supplement in children with allergic asthma and rhinitis: The INAPRA study. Int Immunopharmacol. 2026;184:116903 PubMed ↗
  2. Bideshki MV, et al. Synbiotic supplementation effects on muscle damage and inflammation in professional futsal players in a randomized clinical trial. Sci Rep. 2026;16: PubMed ↗
  3. Pretorius RA, et al. Body mass index, prebiotic supplementation during pregnancy and gestational diabetes mellitus risk: an effect modification analysis from a randomised controlled trial. Nutr J. 2026;25: PubMed ↗

Safety & who should check first

FOS is widely recognised as safe and gentle at standard daily doses up to 10 grams. Taking very large single amounts over 15 grams at once may cause temporary mild gas, flatulence, or bloating.