Understand prebiotics and probiotics

Probiotics and prebiotics have been gaining in popularity as a health food in the U.S. for the past 10 years. It may not seem like there is much of a different between the two but they have different types of bacteria and come from different sources.


Prebiotics are a type of fiber that is naturally found in certain foods.  Prebiotics fall into three categories: 

  • fermentable dietary fibers (whole oats, rolled oats, psyllium seed husk, xanthan gum, etc.)
  • Resistant Starches

           RS1 (seeds, legumes, unprocessed whole grains)

           RS2 (garlic, green banana, artichokes)

           RS3 (cooked legumes, bread, cornflakes, potatoes, pasta)

undigestible oligosaccharides (legumes, plants)

If consumed regularly, prebiotics can be useful in the diet to help alleviate obesity, improve calcium absorption, prevent chronic disease and improve gastrointestinal health.


Probiotics are live microorganisms, or good bacteria, that are added to yogurt, dairy products and beverages. They can also be found sold in supplemental form.   

Probiotics are good for the immune system and improve the health of the digestive tract, preventing the onset of colon cancer. Two of the most well-known bacteria, Bifidobacteria and Lactobacilli, help balance the gut microflora by increasing the number of beneficial bacteria and reducing the harmful bacteriaYogurt that contains a good amount of live and active cultures may be helpful for those who suffer from lactose intolerance.

Stephanie Clark, associate professor of food science and human nutrition and member of the ISU Dairy Team, said, “I buy yogurt of many kinds because I believe in the health benefits of yogurt and the bacteria in yogurt. Although not all yogurts have documented beneficial probiotic bacteria, there is plenty of research to show the benefits of consuming yogurt. Activia is a good product for those with constipation. The research has been done to validate the beneficial effects so they can make the claims that they do and give you your money back if you don’t benefit.”