When hearing “gut health,” the brain may not be the next thing that immediately comes to mind. However, they are largely connected through the gut microbiome and their bi-directional communication network called the gut-brain axis.

The gut microbiome consists of living organisms, such as bacteria, that live in our gut and play a major role in immune health and numerous other functions. The gut-brain axis has several pathways; including anatomical, neurological, endocrine, and immune mechanisms.

How can the gut-brain axis affect our mood?

Dysbiosis of the gut microbiome is becoming increasingly recognized as a major contributor to stress-related disorders, depression, and anxiety. Dysbiosis is the imbalance that can occur between the “beneficial” and “harmful” organisms that live in our gut. When they are out of balance, this leads to a variety of health issues.

The gut produces approximately 95% of the body’s serotonin, the “happy hormone” that produces a sense of well-being and promotes learning and memory. The gut produces serotonin through the bacterial fermentation of dietary carbohydrates, which produces short-chain fatty acids that help regulate the release of serotonin.

Additionally, the microbiome acts as a protector of the gut lining, ensuring that harmful bacteria and the metabolites that they produce do not get absorbed into the bloodstream.

When there is a decrease in beneficial gut bacteria, intestinal permeability is increased, a phenomenon known as “leaky gut syndrome.” This increased intestinal permeability allows foreign substances to pass through the gut lining and enter the bloodstream where they do not belong. Here, these substances cause an increase in inflammation and can actually block the production of neurotransmitters that help us feel happy. Other symptoms may include fatigue, gas, bloating, joint and muscle pains, skin rashes, and can even contribute to chronic diseases such as diabetes and heart disease.

How can I keep my gut healthy?

A healthy microbiome is not only about having a large number of bacteria present, but also about having a variety of beneficial strains.

A large and diverse community will assist with nutrient absorption, hormonal balance, immunity, bowel regulation, and many other functions of the body. An abundance of factors that may negatively influence the microbiome; including antibiotic use, lack of physical activity, prolonged stress, lack of sleep, and poor diet.

Below are a few recommendations to enhance your gut health:

Choose the right carbohydrates, and fiber: Carbohydrate-laden foods may contain fiber, and it is important to include the right kinds of carbohydrates to maximize your fiber intake. Fiber is an important element to support your gut health as it provides prebiotics, the ‘food’ for gut bacteria. The AHA recommends consuming a minimum of 25 grams of dietary fiber per day. High fiber foods include vegetables, fruit, whole grains, beans, legumes, nuts, and seeds.

Anti-inflammatory foods: An inflammatory diet can negatively impact gut health and lead to numerous health problems. Foods that cause an inflammatory effect are processed and fast foods, fried foods, sugary foods and beverages. Opting for anti-inflammatory foods can decrease inflammation leading to a healthier gut and better mental health. Some foods that can have anti-inflammatory qualities include salmon, avocados, dark chocolate, green tea, turmeric, chia seeds, berries, nuts, spinach, and garlic.

Fermented foods and probiotics: Probiotic food sources are considered to be “living.” They help populate the gut microbiota and promote the bacteria that is helpful to gut health. Sources of these types of foods include sauerkraut, kimchi, miso, kefir, pickled vegetables, yogurt, and kombucha. Including these fermented and probiotic containing foods in your diet can improve gut health and lead to positive health outcomes.
Variety: It is easy to fall in to the rut of eating the same two vegetables every week, but having a varied diet helps diversify the gut. Try including as many different colors in your diet as you can. If you find that you are eating mostly orange fruits and vegetables, try mixing in some greens and berries. The food we eat provides nourishment for the bacteria in our gut, so having a diverse diet can help lead to a diverse microbiome.

This article was written by Kristin Gerhardt and Emily Pierce, dietetic interns with Cox College.

Resources

Appleton, J. (2018). The gut-brain axis: influence of microbiota on mood and mental health. Integrative Medicine: A Clinician’s Journal, 17(4), 28–32. Retrieved from http://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=133088184&site=ehost-live&scope=site

Cresci, G. A., & Bawden, E. (2015). Gut microbiome: What we do and don’t know. Nutrition in Clinical Practice, (1). https://doi.org/10.1177/0884533615609899

Stewart, E. A. (2016). Leaky gut syndrome. Today’s Dietitian. 18(1), 46-53. Retrieved from http://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=112385237&site=ehost-live&scope=site

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