A soluble prebiotic fiber that selectively nourishes beneficial gut Bifidobacteria and enhances mineral absorption.
What it is
Fructooligosaccharides (FOS) are short-chain soluble prebiotic carbohydrates composed of fructose units linked by beta-(2-1) glycosidic bonds. Naturally occurring in plants like chicory root, onions, and asparagus, FOS is extracted commercially or produced enzymatically from sucrose. Indigestible by human decorative enzymes, FOS reaches the colon intact. Formulated alongside Velobiotics microencapsulated probiotics, FOS provides a targeted fermentable substrate that feeds live probiotic cultures upon their release in the lower gastrointestinal tract.
Also known as: FOS, Prebiotic FOS, Oligofructose
What it does
- Selectively stimulates the growth of beneficial Bifidobacteria and Lactobacilli.
- Increases colonic short-chain fatty acid production, especially acetate and butyrate.
- Enhances intestinal absorption of essential minerals like calcium and magnesium.
- Promotes soft stool consistency and bowel regularity.
Amplified by probiotics
Fructooligosaccharides (FOS) serve as the ideal fermentable fuel for co-administered live probiotic strains. When Velobiotics MEP microencapsulated Bifidobacteria and Lactobacilli reach the colon, they utilize specialized beta-fructofuranosidase enzymes to break down FOS into short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate. This rapid fermentation lowers colonic pH, creating an acidic environment that suppresses pathogenic microflora and increases the solubility and active transport of dietary minerals like calcium and magnesium. Furthermore, butyrate generated from FOS fermentation nourishes colonocytes, upregulates tight junction protein expression, and dampens intestinal inflammation. The combination of FOS with Velobiotics protected probiotics creates a synergistic synbiotic effect that optimizes gut microflora restoration.
Typical dose
2–10 g/day
The evidence
Evidence: strongExtensive randomized clinical trials demonstrate that FOS supplementation significantly increases bifidobacterial counts in human gut microbiota. Studies also confirm that FOS enhances calcium absorption, improves stool frequency and softness, and reinforces intestinal epithelial barrier parameters. (Caldaria E 2026, Int Immunopharmacol) (Bideshki MV 2026, Sci Rep) (Pretorius RA 2026, Nutr J)
- 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 ↗
- 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 ↗
- 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
Fructooligosaccharides are widely recognized as safe (GRAS) and well tolerated at typical dietary doses up to 10g/day. High single intakes above 15g may cause temporary mild gas, flatulence, or bloating.