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Eating Well for Gut Health

Updated: Mar 8, 2023

Learn more about why gut health matters and how you can eat well to keep your gut healthy.

Over the past few years “gut health” has become an increasingly popular topic in the health and nutrition world. You may have heard the term in the media, on social media posts, blog posts, YouTube videos, medical journals, and sometimes stamped onto food labels. The message around gut health is generally simple- keep your gut healthy and you will see a range of benefits including improvements to your digestion, mental health and immunity.

But is there any truth to these claims? What does “gut health” really mean anyway? Is it the solution to all health problems? Should you start taking a probiotic supplement? Or perhaps drinking Kefir everyday? This article will help you better understand the research around gut health and outline a few evidence-based tips for improving your gut health.

What is Gut Health?

Gut health broadly refers to the interactions your body has with the intricate population of bacteria that live in your intestines. On average, each person carries trillions of microbes which belong to about 600,000 different species, most of them living in the large intestine (1). Most of these are beneficial and live in a mutually beneficial relationship with our body. In fact, the cells in our bodies are actually only 10% human and 90% microbes (2). The word “microbiome” refers to the DNA of these microbes and scientists are discovering some gut microbiomes are associated with better health, body composition, and even mental health. The good news is that you can figure out what could improve your gut microbiome with good nutrition.

How Your Gut Microbiome Can Influence Your Health

Bacteria is usually associated with illness so it seems unlikely that more bacteria would be good, but it's true! The gut microbiome is important for digestion and making essential nutrients available for your body to use. It plays a role in the immune system by keeping harmful bacteria at bay and preventing them from getting into the bloodstream through the intestine.

There is also a lot of new evidence that a healthy microbiome plays an important role in mental health and may reduce depression and anxiety (3). It may also influence metabolic health, skin disease (including acne and eczema), autoimmune disease and even some cancers but the exact ways the gut microbiome determines health or disease is complex. The ideal gut microbiome is not known, but the amount of different good bacteria, called a “diverse microbiome”, is likely the most important aspect. There are still unknowns when it comes to the microbiome but scientists agree that it is fundamentally important for your health.

Are There Any Foods That Negatively Affect the Gut Microbiome?

Stress, a lack of proper sleep, eating a high sugar diet or one rich in processed foods, and taking antibiotics often can wreak havoc on your microbiome. In fact, it’s possible to have a pretty good idea of your diet just by looking at your gut biome, that’s how important the food you eat is! If you eat a “western diet” (high in sugar and saturated fats), a restrictive diet, a “fad” diet, or a diet without food diversity your microbiome may not be as optimal as it could be.

Some symptoms of poor gut health can include bloating, gas, constipation, diarrhoea and even fatigue or low mood. A dysfunctional gut microbiome is also associated with diseases like irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) (ulcerative colitis and Crohn's disease), type 2 diabetes, cardiovascular disease and colorectal cancer (4). Of course, some of the causes are unavoidable, like taking necessary antibiotics. However, there are things you can do, like increasing your intake of prebiotics and probiotics, to improve the diversity of your microbiome and increase the number of beneficial bacteria.

What Can I Eat to Improve My Gut Health?

Eating the right foods can help optimize your gut microbiome. You may have heard the term probiotics and prebiotics- these are two key pieces of the puzzle when it comes to gut health.

Probiotics are the beneficial microorganisms that are found in foods and supplements. Probiotics are beneficial to your body for a variety of reasons. Probiotics can:

  • stop possibly harmful bacteria and microbes from getting out of control(5) C.difficile infection and small intestinal bacterial overgrowth (SIBO) are examples of bad bacteria getting out of hand.

  • improve the barrier between the intestines and the bloodstream stopping these harmful microbes from entering the bloodstream (5)

  • play a role in immunity and can influence the development of conditions such as allergy, asthma and autoimmune disorders (6)

  • influence the production of brain chemicals, called neurotransmitters which regulate emotions (5)

Examples of beneficial probiotics are usually Lactobacillus and Bifidobacterium (4) which are found primarily in fermented foods. Probiotic foods include:

  • Probiotic yogurt (regular yogurt may not contain any live probiotics)

  • Kefir

  • Sauerkraut

  • Kimchi

  • Tempeh

  • Miso

Prebiotics are foods you eat that create an ideal environment in the gut for your good bacteria to live, grow, and reproduce. These are carbohydrates that the body is unable to digest, like fibre. As a general rule, it’s important to include a wide variety of plant foods in your diet. Plants foods are a source of fibre, and there is evidence to suggest that diets high in fibre are associated with better gut health. Examples of plant food include: whole grains, nuts and seeds, legumes (beans, chickpeas, lentils) and fruits and vegetables. Keep in mind that if your diet is currently low in fibre, it's best to introduce fibre rich foods into your diet gradually. This will help prevent any digestive discomfort like bloating, constipation and diarrhea. Foods rich in prebiotics include:

  • Unripe bananas

  • Asparagus

  • Onions

  • Berries

  • Legumes

You may not have heard of postbiotics, but they are one more thing that may be able to improve gut health in humans. Postbiotics are enzymes, sugars, proteins, organic acids and other cell components released by probiotics. These substances can be found in foods rich in probiotics but higher, controlled doses are available in supplement form. These may have anti-inflammatory and antioxidant properties, and there is research looking into the potential of postbiotics to regulate the immune system, prevent high blood pressure, high cholesterol and possibly obesity (6). These may be more safe and effective for people with gut diseases like IBD. However, these are still in the early stage of development and research so it's best to wait for clear research.

It's always important to note that prebiotics, probiotics and possibly postbiotics are just one aspect of gut health. Taking a holistic approach that involves nutrition, exercise, sleep, and healthy stress levels is key when you are trying to improve your gut health.

Should I Be taking a Prebiotic or Probiotic supplement?

Generally speaking, it is best to get prebiotics and probiotics from food. Food and lifestyle changes are the safest and most sustainable way to gradually improve your gut microbiome. There is no clear evidence that taking probiotic supplements just for the sake of it will improve your gut health if you have no digestive conditions or symptoms. Probiotic supplements may be beneficial for some individuals who have specific digestive symptoms or digestive conditions like IBS, and for people who have taken antibiotics. Keep in mind that different strains of probiotics work for different conditions. Probiotics may also pose a risk for people who have cancer or weakened immune systems. This is why it’s important to talk to a dietitian, doctor and pharmacist if you are thinking about starting a probiotic.

Time to Focus on Your Gut Health

Gut health is crucial to overall health but it can easily be overlooked in the bustle of everyday life. How you eat has the ability to alter your gut health. While the root of gut issues can be complicated we know with some confidence that diet is a key piece of the puzzle. The increasing interest in gut health has led to a surge in information and products on the market claiming to be miraculous cures for all sorts of health issues. Keep in mind that if something is too good to be true, it usually is.. First things first- if you are experiencing serious digestive issues talk to your doctor. They may need to run some tests to determine what the issue is. A dietitian can also help determine what foods may be causing digestive issues like stomach upset and bloating and how to improve your microbiome in a safe and sustainable way.

Co-written by: Clare Zasowski, Nutrition Student and Niloufar Deilami, RD MPH


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  3. Sandhu, K. V., Sherwin, E., Schellekens, H., Stanton, C., Dinan, T. G., & Cryan, J. F. (2017). Feeding the microbiota-gut-brain axis: diet, microbiome, and neuropsychiatry. Translational Research.

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  6. Mezouar, S., Chantran, Y., Michel, J., Fabre, A., Dubus, J. C., Leone, M., … Vitte, J. (2018). Microbiome and the immune system: From a healthy steady-state to allergy associated disruption. Human Microbiome Journal.

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  8. C. A. Lozupone, J. I. Stombaugh, J. I. Gordon, J. K. Jansson, and R. Knight, “Diversity, stability and resilience of the human gut microbiota,” Nature, vol. 489, pp. 220–230, 2012.

  9. Krumbeck, Janina A.; Maldonado-Gomez, Maria X.; Ramer-Tait, Amanda E.; Hutkins, Robert W. Prebiotics and synbiotics, Current Opinion in Gastroenterology: March 2016 - Volume 32 - Issue 2 - p 110-119 doi: 10.1097/MOG.0000000000000249

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