Skip to main content

By: Haley Singer, Undergraduate Student in Food Science and Human Nutrition at the University of Illinois Urbana-Champaign

Pre vs Pro

Pre- and probiotics help maintain a healthy gut by balancing bacteria in the intestines. This healthy balance creates an environment that’s suitable for other microbes to flourish.  Probiotics are microorganisms that are known to offer a health benefit. These are often found in fermented foods such as kimchi and yogurt. Prebiotics, on the other hand, are food components that are used by microbes. They, too offer a health benefit.  We can simply think of prebiotics as food for our gut bacteria.

 Probiotics for Different Health Conditions

There is growing research on the important role pre and probiotics play with gastrointestinal disorders.1 Different types of probiotics may provide different health effects. Here are some common health conditions and related research on probiotics:2

Inflammatory Bowel Disease (IBD): A decrease in microbial diversity is noted in patients with IBD. Although the causal link is not yet determined, this shows how probiotics may play an important role.2 Research suggests that probiotic use may be important for IBD management. Some literature suggests that probiotics may aid in reducing the signs and symptoms for these diseases. Low levels of certain bacterial species have been associated with active periods of IBD. Using a probiotic supplement of that bacterial species may help to induce remission.

Irritable Bowel Syndrome (IBS): Some clinical trials have demonstrated the possible use of probiotics for symptom improvement in IBS patients. 2 This research has shown the beneficial effects of using certain probiotic strains, but the placebo effect may be at play here.

Allergies: The increase of allergies in the industrialized world can be explained by increased hygiene, leading to gut microbiota alterations. 2 Studies have looked at the difference in gut microbes in children with allergies and without and have demonstrated the effects probiotics have on some allergic diseases in high risk families. These results are promising in that continued research will help us to further understand the relationship between probiotics, the gut microbiota, and allergies.

Diabetes and Obesity:2 Some studies in mice and humans have shown a possible link between microbiota and both obesity and type 2 diabetes. 2 The effect of probiotic introduction on these disease states is not yet known. Due to the high prevalence of these two diseases, more research is needed in this area.

Potential Health Benefits of Probiotics:

The effects of probiotics on our bodies is still a relatively new area of study. There is a lot of research underway that will help us better understand the benefits of probiotic use. Below are listed some of the possible benefits.3

    • Improve gut microbiota
    • Enhance the immune system
    • Reduce blood cholesterol
    • Cancer prevention
    • Treatment of bowel diseases
    • Reduce risk of high blood pressure
    • Reduce lactose intolerance
    • Prevention/treatment of bowel diseases
    • Alleviation of post-menopausal disorders

Along with these benefits, research suggests that we may also see the following effects from probiotic consumption: improved oral and skin health and anti-anxiety and depression-relieving effects. There is a need for more research to be conducted on probiotic use to be certain about these suggestions.3

Tips for choosing probiotic foods and supplements

A majority of probiotics are sold as dietary supplements. This means they don’t require FDA approval before they are put on the market. If the probiotic were to be marketed as a drug for a specific treatment purpose, then it would require FDA approval for safety and regulation.4

When choosing supplements here are a few things to look for.5

    1. The package should indicate that the supplement contains live and active bacterial cultures.
    2. It is generally recommended to choose probiotic supplements with at least 1 billion colony forming units.
    3. It should contain bacteria from the genus Lactobacillus, Bifidobacterium or Saccharomyces boulardii. These are the most researched probiotics and are generally regarded as safe.

According to the research, foods  containing probiotics  over supplements are preferred. These foods provide a nourishing environment for the probiotics and they have beneficial effects on immunity, inflammation, and cholesterol. 5

Dietary sources of probiotics:

    • Yogurt
    • Kombucha (fermented black-teas)
    • Kimchi & sauerkraut (fermented cabbage)
    • Tempeh and miso (fermented soy)

 Prebiotics: Feeding your bacteria

What we eat is probably the biggest influence on our gut microbiota. Probiotics like to feed on fermentable fiber, which is where prebiotics come to play. Both probiotics and prebiotics work together to support a healthy gut environment.5

Dietary sources of prebiotics:

    • Dried beans and legumes
    • Garlic
    • Asparagus
    • Onions and leeks
    • Green bananas
    • Wheat



  1. Cremon C, Barbaro MR, Ventura M, Barbara G. Pre- and probiotic overview. Current Opinion in Pharmacology. 2018;43:87-92. doi:10.1016/j.coph.2018.08.010
  2. Butel M-J. Probiotics, gut microbiota and health. Published November 28, 2013. Accessed May 10, 2021.
  3. Shi LH, Balakrishnan K, Thiagarajah K, Mohd Ismail NI, Yin OS. Beneficial Properties of Probiotics. Tropical Life Sciences Research. 2016;27(2):73-90. doi:10.21315/tlsr2016.27.2.6
  4. Probiotics: What You Need To Know. National Center for Complementary and Integrative Health. Accessed May 10, 2021.
  5. Team DH. How to Pick the Best Probiotic for You. Health Essentials from Cleveland Clinic. Published October 9, 2020. Accessed May 10, 2021.

photo by Daria Shevtsova from Pexels