Prebiotics are a family of non-digestible, fermentable carbohydrates (soluble dietary fiber).1 Prebiotics are not digested or absorbed in the stomach or small intestine, but instead reach the colon intact, where they are fermented and serve as a food source for beneficial probiotic bacteria, such as: bifidobacteria and lactobacilli, and then exerting health benefits.1,2

Common Forms

  • FOS (Fructooligosaccharides): FOS is family of short-chain, non-digestible fructans (containing a chain of fructose molecules in non-digestible linkages). FOS can be produced from enzymatic hydrolysis of inulin or derived from beets using a water-extraction method. Food sources of FOS include: onion, asparagus, bananas, Jerusalem artichoke and chicory.1
  • Inulin: Inulin is a mixture of long- and medium-chain, non-digestible fructans.2 Inulin is extracted from chicory (Chicorium intybus) roots using a water-extraction process, then purified, and spray-dried into a powder form. Inulin can be also found in foods such as: onion, asparagus, bananas, Jerusalem artichoke and chicory.1

Major Health Benefits

FOS and inulin are dietary soluble fibers that work as prebiotics by promoting the growth of beneficial gut bacteria (probiotics) that can improve gut health and regularity (e.g., reducing constipation or diarrhea), but they do not promote the growth of pathogenic bacteria.1,3-5 Intake of FOS and inulin has been shown to provide positive effects in maintaining healthy immune system, decrease blood cholesterol and fat (triglycerides) levels, and increase mineral absorption (e.g., Iron or Calcium).1,4,6,7 Therefore, it is suggested that prebiotic consumption may be associated with lower risk of osteoporosis, cardiovascular disease, obesity, and type 2 diabetes as well as problems related to intestinal disturbances.6,8 ­


In certain people, consumption of rapidly fermentable prebiotics may cause GI distress, such as: bloating and flatulence.9


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  8. Roberfroid MB. Prebiotics and probiotics: are they functional foods? Am J Clin Nutr. 2000 Jun;71(6 Suppl):1682S-7S. PMID: 10837317.
  9. Kaur A, Rose DJ, Rumpagaporn P, Patterson JA, Hamaker BR. In vitro batch fecal fermentation comparison of gas and short-chain fatty acid production using “slowly fermentable” dietary fibers. J Food Sci. 2011 Jun-Jul;76(5):H137-42. doi: 10.1111/j.1750-3841.2011.02172.x. Epub 2011 Apr 27. PubMed PMID: 22417432.