Fructo-oligosaccharides (FOS) and Other Oligosaccharides

Also indexed as: Inulin Oligosaccharides, Oligosaccharides

The term “oligosaccharide” refers to a short chain of sugar molecules (“oligo” means “few” and “saccharide” means “sugar.”) Fructo-oligosaccharides (FOS) and inulin, which are found in many vegetables, consist of short chains of fructose molecules. Galacto-oligosaccharides (GOS), which also occur naturally, consist of short chains of galactose molecules. These compounds can be only partially digested by humans.¹ ² ³ ⁴ When oligosaccharides are consumed, the undigested portion serves as food for “friendly” bacteria, such as Bifidobacteria and Lactobacillus species.

Where is it found?

FOS and inulin are found naturally in Jerusalem artichoke, burdock, chicory, leeks, onions, and asparagus. FOS products derived from chicory root contain significant quantities of inulin,⁵ a fibre widely distributed in fruits, vegetables and plants, which is classified as a food ingredient (not as an additive) and is considered to be safe to eat.⁶ In fact, inulin is a significant part of the daily diet of most of the world’s population.⁷ FOS can also be synthesised by enzymes of the fungus Apergillus niger acting on sucrose. GOS is naturally found in soybeans and can be synthesised from lactose (milk sugar). FOS, GOS, and inulin are available as nutritional supplements in capsules, tablets, and as a powder.

FOS, GOS, and inulin have been used in connection with the following conditions (refer to the individual health concern for complete information):

Science Ratings	Health Concerns
	Elevated triglyceride levels
	Pre- and post-surgery health Type 2 diabetes
Reliable and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit. For a herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Science Ratings

Health Concerns

Elevated triglyceride levels

Pre- and post-surgery health

Type 2 diabetes

Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars

Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star

For a herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Who is likely to be deficient?

As FOS, GOS, and inulin are not essential nutrients, no deficiency state exists.

How much is usually taken?

The average daily intake of oligosaccharides by people in the United States is estimated to be about 800 to 1,000 mg. For the promotion of healthy bacterial flora, the usual recommendation for FOS, GOS, or inulin is 2,000 to 3,000 mg per day with meals. In the studies on diabetes and high blood lipids (cholesterol and triglycerides), amounts ranged from 8 to 20 grams per day.

Are there any side effects or interactions?

Generally, oligosaccharides are well tolerated. Some people reported increased flatulence in some of the studies. At higher levels of intake, that is, in excess of 40 grams per day, FOS and the other oligosaccharides may induce diarrhoea.

There is a report of a 39-year old man having a life-threatening allergic reaction after consuming high amounts of inulin from multiple sources, including FOS.⁸ Allergy to inulin in this person was confirmed by laboratory tests. Such sensitivities are extremely rare. People with a confirmed sensitivity to inulin should probably avoid FOS.

At the time of writing, there were no well-known drug interactions with Fructo-oligosaccharides (FOS) and Other Oligosaccharides.

References

1. Molis C, Flourie B, Ouarne F, et al. Digestion, excretion, and energy value of fructooligosaccharides in healthy humans. Am J Clin Nutr 1996;64:324-8.

2. van Dokkum W, Wezendonk B, Srikumar TS, van den Heuvel EG. Effect of nondigestible oligosaccharides on large-bowel functions, blood lipid concentrations and glucose absorption in young healthy male subjects. Eur J Clin Nutr 1999;53:1-7.

3. Alles MS, Hautvast JGA, Nagengast FM, et al. Fate of fructo-oligosaccharides in the human intestine. Br J Nutr 1996;76:211-21.

4. Roberfroid M. Dietary fibre, inulin and oligofructose. A review comparing their physiological effects. Crit Rev Food Sci Nutr 1993;33:103-48 [review].

5. Duke JA. Handbook of phytochemical constituents of GRAS herbs and other economic plants. Boca Raton, FL: CRC Press, 1992.

6. Carabin IG, Flamm WG. Evaluation of safety of inulin and oligofructose as dietary fiber. Regul Toxicol Pharmacol 1999;30:268–82 [review].

7. Coussement PA. Inulin and oligofructose: safe intakes and legal status. J Nutr 1999;129:1412S-7S [review].

8. Gay-Crosier F, Schreiber G, Hauser C. Anaphylaxis from inulin in vegetables and processed food. N Engl J Med 2000;342:1372 [letter].

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The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or chemist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires August 2007.