What is Inulin Fiber?

jerusalem-artichoke-xsInulin (not to be confused with insulin) is a carbohydrate found in a lot of plants, and is used by the plants as an energy reserve but also helps the plants survive cold and drought.  Inulin has a lot of uses, but it’s as a prebiotic that interests us.

When we eat inulin, it passes through the gut where it is fermented by the good bacteria in the large intestine.  This fermentation process feeds the good bacteria.  In particular, inulin has been shown to stimulate certain Lactobacillus, especially the bifidus species.  These bacteria can ferment the inulin to produce short chain fatty acids that may benefit the liver and help reduce the risks of some forms of cancer.

Food rich in inulin

Chicory root has perhaps the highest concentration of inulin and it’s this plant that is often used in the extraction and purification of inulin using a system that is similar to the way sugar is extracted from sugar beet.  Extracted inulin is used as a dietary supplement, or added to “functional” foods to help feed the good bacteria.  They can also help improve the taste and texture of processed foods.  Inulin can also be used in the manufacture of low fat cheeses and frozen deserts.

When it comes to plants rich in inulin, think roots and starchy tubers.  Here is a list of some plants that contain inulin. Top sources of inulin include:

  • Chicory root
  • Jerusalem Artichokes
  • Jicama

While lesser amounts are also found in:

  • Leeks, Garlic & Onions
  • Bananas
  • Dandelion roots

So the good news is that inulin, one of the best prebiotics available to us, is found in the food we eat.  Eating more healthy vegetables and fruit, especially those listed above, is a great start to improving digestion and health through feeding the good bacteria.  The levels we get in the diet are probably lower than those used in scientific studies, so you may also want to take an inulin supplement for maximum health benefits.

Other Health Benefits of Inulin

Besides being a great prebiotic, inulin is also thought to:

  • Support a healthy inflammation response.
  • Increase fat metabolism and be especially useful in reducing the dangerous visceral fat that is stored around our organs.
  • Increase absorption of key minerals from the gut, like calcium, magnesium and iron.
  • Decrease levels of ghrelin, which is a hormone that makes us hungry.

Side Effects of Inulin?

While inulin is clearly beneficial to our overall health, too much may lead to an overgrowth of bacteria, bloating, flatulence and diarrhea.

To limit your chances of side effects, start off with very low doses of inulin if you want to take it as a dietary supplement.  You probably should start with 5-10g a day, or indeed, just start eating more of the foods listed in the “Foods rich in inulin” section of this article.

If you are allergic to foods like artichokes, please do consult your doctor before considering inulin as a supplement.  While bad reactions to inulin are rare, there is one study I read online where a women went into anaphylactic shock after eating health foods containing inulin.


  1. http://www.ncbi.nlm.nih.gov/pubmed/20497775
  2. https://www.andeal.org/vault/2440/web/JADA_Fiber.pdf
  3. http://jn.nutrition.org/content/129/7/1412S.full
  4. http://www.karger.com/Article/Abstract/83323

About Andy

Most people are totally unaware that millions of bugs exist in our gut. Even more people don't realize that these bugs are vital to our health and represent out first line of defense against disease. Andy Williams has a Ph.D. in animal physiology, and a strong interest in health & vitality. This site showcases one of his interest - the gut microbiome, and how it affects our health.

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