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By Sarah Pittman, Human Nutrition Graduate Student at the University of Illinois

Food plays a big part in our society today. Food is not only used for nourishment and fuel for our bodies, but we also use it for celebrating, gathering and enjoyment. But the food we put into our bodies has a major impact on our gut-brain axis. Studies have shown that lower grade fuel (more processed and not as healthy food) can contribute to depression and cognitive health in adults. They have found that specifically, the western diet is associated with a smaller hippocampus, the part of the brain that regulates emotion and memory.8

Free Radicals

Free radicals are the natural by products of chemical processes like metabolism. Although too many free radicals can cause damage to the body, they are also essential to life. When we eat lower grade fuel excess free radicals form, which can cause damage to cells, proteins and DNA. Free radicals are associated with cancer, atherosclerosis, Alzheimer’s disease and Parkinson’s disease.6

Luckily, eating foods that contain antioxidants, like berries, red cabbage and kale, help to lessen or prevent the effects of free radicals by preventing the oxidation of other molecules.4

Gut Microbiome and the Gut-Brain Axis

The gut microbiome is composed of over 100 trillion microbes, in which 95% of the bacteria in our bodies live in our GI tract. The gut bacterium has many functions including, digestion, immunity with fighting off infection, production of vitamins (especially vitamins B & K), as well as communication with the brain, hence the correlation to diet and mental health.8

The gut-brain axis is a complex network that integrates the gut microbiome with the nervous system in the brain through the vagus nerve.7 This network regulates gastric and intestinal function as well as energy homeostasis.7 This is why an unhealthy digestive system can be linked to mental and physical distress.8

How to maintain a healthy gut

Research has shown that we can slightly alter the composition of our gut microbiota (for better or worse) within a matter of 24 hours.8

Protein foods contain the building blocks of the body and brain chemicals that influence how we think and feel.8 Therefore, including a lean protein source at each meal can lead to a healthy gut.

Omega 3 fatty acids are very beneficial to brain health. Not having omega 3’s in the diet can change the makeup of the microbiome, which can ultimately influence brain health and behavior. A low intake of omega 3’s has been correlated with depression, poor concentration and fatigue.8

As mentioned before, eating a diet rich in antioxidants can help fight free radicals in the body. Eating a diet rich in berries, pecans and even dark chocolate can help maintain a healthy microbiome!2,8

Staying hydrated is so important for all body functions and processes, including digestion and elimination. Dehydration affects our ability to think clearly and concentrate.3,8

Probiotics and fiber can also help to maintain a healthy digestive tract. Probiotics are a type of beneficial bacteria found in the gut.8 But probiotics are also found foods/drinks like yogurt, sauerkraut and kombucha.1,8 Fiber found in fruits and vegetables, nuts, beans and whole grains can positively impact the gut microbiome by feeding the billions of bacteria in our gut.5

Overall eating a healthful diet that is rich in fruits, vegetables, fiber, antioxidants and water can help maintain a healthy gut microbiome, which in turn will impact your overall mental and physical health!



  1. 8 Greatest Probiotic Foods You Should Be Eating – Dr Axe. Dr. Axe. Published 2019. Accessed May 30, 2019.
  2. 12 Healthy Foods High in Antioxidants. Healthline. Published 2019. Accessed May 30, 2019.
  3. Chris Iliades M. The Importance of Water in Your Diet Plan.
  4. Debra Rose Wilson C. Free radicals: How do they affect the body?. Medical News Today. Published 2019. Accessed May 30, 2019.
  5. Fiber Is Good for You. Now Scientists May Know Why. Published 2019. Accessed May 30, 2019.
  6. Published 2019. Accessed May 30, 2019.
  7. The Microbiome-Gut-Brain Axis Relies on Your Vagus Nerve. Psychology Today. Published 2019. Accessed May 30, 2019.
  8. Smith M, Pate B. Food and Mood. Presentation presented at the: 2019; Rosecrance.

Photo on Unsplash by: Pablo Merchan Monte.