Prebiotics & Probiotics

Probiotics and prebiotics are growing in popularity as research is discovering their relationship with the microbiome and human health. The microbiome is a term used to describe the dynamic collection of microbes (eg. Bacteria) found in the human intestines. Many of these microbes have a symbiotic relationship with humans; this means that both species benefit from one another. For example, bacteria can produce vitamins, aid with digestion, and destroy disease-causing microorganisms.1However, harmful microbes also exist and may contribute to some health problems. The reason why probiotics and prebiotics are becoming popular is because they have been shown to support the growth of beneficial microorganisms in the intestines, which may in turn improve our digestion.

Prebiotics and probiotics work together to foster a healthy digestive system in the human body. Prebiotics are non-digestible parts of carbohydrate foods that feed beneficial microorganisms in the large intestines. Probiotics are live beneficial microorganisms that are also naturally present in the large intestine. You may be thinking, if they are naturally present, then why do people consume them? Probiotics are consumed because the microbiome is a dynamic system, meaning that different factors such as stress, certain foods/beverages (eg. alcohol), and some medications (eg. antibiotics) can decrease the presence of beneficial microbes. Probiotics simply help bring the microbiome back into balance. The positive effects of probiotics will vary between individuals and they will depend on the quantity eaten and the type of probiotic; however, more does not necessarily mean better.2It is still unknown how many probiotics are needed in order to reap any health benefits, however, it is suggested that they should be consumed regularly as part of a balanced diet for a long period of time to support the microbiome.2Although probiotics are safe for most individuals, they may cause gas, bloating, and diarrhea in some people.

Prebiotics and probiotics are naturally found in many foods. Some food sources of prebiotics include: garlic, leek, onion, psyllium husk, wheat bran, bananas, whole grains, tomatoes, and potatoes. Food sources of probiotics include: yogurt, cheese, kefir, and fermented vegetables such as sauerkraut. Foods such as juice, cereal, chocolate, and ice cream may also be fortified with probiotics.2It is important to read food labels to make sure that these foods contain live bacteria, otherwise the pasteurization process destroys them and they are not added back in. The types of probiotics that are often added to food products are Lactobacillusand Bifidobacterium.2  Both prebiotics and probiotics can also be found in a supplement form, but they are not necessary for good health and there is no guarantee that they are effective.2Consult a doctor or dietitian if you would like to take such supplements. 

Research shows that the consumption of probiotics may support the gastrointestinal tract. Probiotics may improve the symptoms of both irritable bowel syndrome and inflammatory bowel disease.2They may also help lessen diarrhea associated with antibiotic consumption.2Furthermore, probiotics may help some individuals with their lactose intolerance, but more research must be done to confirm this.2

Multiple direct and indirect pathways have been discovered between the gut and brain, which has led to a new phenomenon referred to as the gut-brain axis.3The gut-brain axis is a term used to acknowledge the relationship between the health of the intestinal microbiome and the health of the brain. For example, an unfavourable microbiome composition may be associated with anxiety and depression.3Therefore, it is suspected that probiotics may potentially benefit mental health as they can rebalance the microbiome by reducing the number harmful microbes and increasing the number of beneficial microbes.4The microbiome also appears to have an effect on immune function, behaviour, and stress response.3,4

More research is needed to fully understand all of the health benefits associated with consuming probiotics and to determine appropriate dosages but we can assume that probiotic-containing foods are safe for most people.2These foods also contain other micronutrients that are needed for good health. The bottom line is that it is not necessary to consume probiotics to be nourished, but they are not harmful in moderation and they may be even be helpful in certain situations. Here at change.creates.change, our dietitians often recommend a probiotic to help with the digestive issues that arise with the refeeding process!


  1. Hibberd, P., Duffy, L., & Shurtleff, D. (2018). Probiotics: in depth. In National centre for complementary and integrative health. Retrieved from:
  2. Dietitians of Canada. (2018). The Pros of Probiotics. In Unlockfood. Retrieved from:
  3. Rieder, R., Wisniewski, P. J., Alderman, B. L., & Campbell, S. C. (2017). Microbes and mental health: A review.Brain, Behavior, and Immunity, 66, 9-17. doi:10.1016/j.bbi.2017.01.016
  4. Dinan, T. G., Stilling, R. M., Stanton, C., & Cryan, J. F. (2015). Collective unconscious: How gut microbes shape human behavior.Journal of Psychiatric Research, 63, 1-9. doi:10.1016/j.jpsychires.2015.02.021

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