What are Prebiotics? And Do You Need Them?

What are Prebiotics? And Do You Need Them?

Bev Dunne

Recently I wrote about the connection between good gut health and our mental health and particularly the importance of probiotics as well as prebiotics in maintaining good gut health.

I’m sure we all know about the importance of probiotics for good gut health, however only more recently has the importance of prebiotics really come to the fore. Probiotics and prebiotics both play an important role in our health however their roles are not the same. Probiotics are the live bacteria which we find in certain foods. Prebiotics on the other hand are a form of soluble, undigestible fibre which as it passes through our digestive system nourishes and feeds our good bacteria. This is important because it enables our healthy probiotics to repopulate and survive.

Some of the foods which are high in prebiotic fibre include chicory root, Jerusalem artichokes, garlic, raw onions, raw asparagus, legumes, bananas and dandelion greens.

There is also a powder known as inulin which is also a soluble fibre and has been found to benefit gut health because of its prebiotic properties. This beneficial powder is often extracted from Jerusalem artichoke or chicory root and has been found to have many health benefits.

Because of its ability to feed our good gut bacteria it is obviously beneficial for our digestive health. It can also be helpful in treating constipation as it has been found, when inulin combines with water it forms a gel like substance which helps lubricate our digestive system thereby relieving constipation. Studies have found people taking inulin improved bowel movements, improved stool consistency, experienced less constipation and improved digestion. (1) One study undertaken over 4 weeks of older adults found by consuming 15g of inulin powder daily they found their digestion improved and they experienced less constipation. (2)

It is understood inulin may be beneficial in regulating our blood sugar levels by helping lower insulin and blood glucose levels after meals.

It has also been found inulin may help reduce calorie consumption helping with weight loss. One study (3) of 44 people with pre-diabetes taking inulin experienced a weight loss of 7.6% of their body weight in comparison with a weight loss of 4.9% in those participants taking cellulose fibre. It appears by including inulin in our diet, we are more likely to eat less because by slowing down the emptying process in our stomach, inulin suppresses the appetite messages to our brain.

Interestingly it is also believed inulin also increases absorption of calcium, enhancing bone mineralization especially in young adolescents. (4) Inulin works by enhancing the acidity in the colon, thereby increasing the surface area, which is then able to absorb more nutrients. This boosts more proteins which in turn enables calcium to bind more readily.

Because inulin passes through the digestive system unabsorbed by digestive enzymes, it takes with it toxins, fat and cholesterol. Because of this action, it has been believed to be helpful in lowering cholesterol

To help boost the growth of good bacteria, increase calcium absorption and help attain regular bowel movements it is suggested to take 10g of inulin a day. Because inulin is a fibre it is best to start slowly with a lower dose, gradually increasing the dosage to twice a day.

Inulin powder can be taken in water, juice, smoothies, yoghurt, cereals or any other foods.  It can also be included in baked goods, even a healthy fruit and nut bar. See my recipe below which is a great nutritious snack.



  1. Nutr Hosp 2014 Aug 1;30(2):244-52.doi:10.3305/mh.2014.30.7565. Luis Collado Yurrita, Ismael San Mauro Martin, Maria Jose Ciudad-Cabanas, Maria Elisa Calle-Puron, Marta Hernandez Cabria
  2. Int J Food Sci Nutr.2011 Mar;62(2) 164-70 doi:10.3109/09637486.2010.527323.Epub2010 Nov 23. Pluiilp Marteau, Heidi Jacobs, Murielle Cazaubiel, Cathy Signoret, Jean-Michael Prevel, Beatrice Housez
  3. Nutr Metab (Lond) 2015 Oct 24:12-36.doi:10.1186/s12986-015-0033-2 eCollection 2105 Nicolas D Guess, Anne Dornhurst, Nick Oliver, Jimmy D Bell, E Louise Thomas, BGary S Frost
  4. Am J Clin Nutr,2005 Aug;82(2):471-6.doi:10.1093/ajcn.82.2.471 Steven A Abrams, Ian J Grifin, Keli M Hawthorne, Lily Liang, Sheila K Gunn, Gretchen Darlington, Kenneth J Ellis