Fructooligosaccharide (FOS)
Fructooligosaccharide (FOS)
Snapshot
Fructooligosaccharides are prebiotic fibers that nourish beneficial gut bacteria, support digestive health, and help regulate blood sugar and mineral absorption.
What is Fructooligosaccharide (FOS)?
Fructooligosaccharides are short chains of fructose molecules linked to a terminal glucose. They resist digestion in the small intestine and are fermented by colonic microbiota, selectively stimulating growth of probiotics like Bifidobacteria and Lactobacilli.
Where It Comes From
FOS occur naturally in foods such as chicory root, onions, garlic, bananas, and asparagus. Commercial FOS is typically extracted from chicory root or synthesized enzymatically from sucrose.
Key Nutrients & Compounds
As a soluble dietary fiber, FOS acts as a fermentable substrate for gut bacteria. It also promotes the production of short‑chain fatty acids (butyrate, propionate, acetate), which nourish colonocytes and support metabolic health.
Health Benefits
FOS enhances gut barrier integrity and regularity by feeding beneficial bacteria, which crowd out pathogens and reduce inflammation. Its fermentation products help maintain healthy colon pH, support immune function, improve mineral (calcium and magnesium) absorption, and may modestly lower blood sugar and cholesterol levels.
Recommended Dosage
Therapeutic doses range from 5 to 15 grams per day, split into two servings. Start at 2–3 grams per day and gradually increase to minimize gas or bloating.
How to Use It
FOS powder dissolves easily in water, juice, or smoothies. It can be incorporated into yogurt, breakfast cereals, or baked goods for a prebiotic boost. Capsules are also available for precise dosing.
Who Should Use It?
Ideal for individuals seeking to improve gut health, support regularity, or enhance mineral uptake. It benefits those undergoing antibiotic therapy, people with mild digestive complaints, or anyone looking to nourish their microbiome.
Possible Interactions or Cautions
Rapid increases can cause gas, bloating, or abdominal discomfort. People with FODMAP sensitivities or IBS should introduce cautiously. Very high doses may have a laxative effect.
Final Thoughts
Fructooligosaccharide is a well‑tolerated, science‑backed prebiotic fiber that fuels beneficial gut bacteria, supporting digestion, immunity, and mineral absorption. Its gentle action and versatility make it an excellent addition to daily nutrition.
Scientific Studies
Gibson, G. R., & Roberfroid, M. B. (1995). Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. Journal of Nutrition, 125(6), 1401–1412. https://doi.org/10.1093/jn/125.6.1401
Roberfroid, M. B., et al. (2010). Prebiotic effects: metabolic and health benefits. British Journal of Nutrition, 104(S2), S1–S63. https://doi.org/10.1017/S0007114510003363
Slavin, J. (2013). Fiber and prebiotics: mechanisms and health benefits. Nutrients, 5(4), 1417–1435. https://doi.org/10.3390/nu5041417