Prebiotics vs. Probiotics

four jars of fermented food


Your gut is naturally full of tiny bacteria that are beneficial for your health. Common terms used to refer to these bacteria include microorganisms, gut microbiota, and flora. They provide many heath benefits, including increasing immunity, absorbing vitamins and minerals, and aiding digestion. This is a hot area of research and each year scientists discover more ways in which gut bacteria affect our health. So, what can you do to optimize the health of beneficial gut bacteria?


Probiotics are foods (or supplements) that contain live cultures which give you benefit when consumed. The term live cultures simply means the food contains living bacteria. When you consume probiotics, these bacteria briefly stay in your gut and help maintain health. There are many different types of bacteria that can be used in these cultures, including lactobacillus and bifidobacterium, both of which have multiple strains. From a health perspective, it is important to have a large amount of “good” bacteria so there is less room for “bad” bacteria in your gut. It is also beneficial to have many different kinds of good bacteria in the gut. To help increase diversity and support good gut bacteria, frequently include a variety of probiotic foods in your diet, such as kefir, yogurt, kimchi, sauerkraut, tempeh, natto, pickles, miso, and kombucha.


It is also important to support the probiotics by consuming prebiotics. Many foods we can’t digest become nourishment for gut bacteria. The human body lacks the enzymes required to break down certain fibers, so they move through the digestive system unchanged. These fibers are the prebiotics, or food for the bacteria. When they reach the gut biome, the bacteria break down the fibers and also produce special acids that nourish the cells in the gut. This process allows us to access the nutrients within the food sources, as well as ensures the bacteria stay plentiful and diverse. Food sources of prebiotics include those typically associated with a high fiber content such as whole grains, fruits and vegetables. A few that are specifically high include barley, flax seed, oats, beans, mushrooms, almonds, onions, leeks, asparagus, apples, cabbage, and bananas. There is no need to go buy expensive supplements to achieve gut health, when it can be accomplished through what you eat.

If you want to learn more about how to incorporate these foods into your diet, make an appointment with a nutritionist at the Bastyr Center for Natural Health or Bastyr University Clinic today. Callie Graff is a dietetic intern with Bastyr University in Kenmore, Washington. She has strong interests in helping others feel empowered to take their health into their own hands through nutrition.


Walfram T. Prebiotics and Probiotics: Creating a healthier you. Academy of Nutrition and Dietetics. 2018.

National Institutes of Health Human Microbiome Project

The International Scientific Association for Probiotics and Prebiotics submission of written comments to the U.S. federal government on the 2015 Dietary Guidelines Advisory Committee