Feeling Blue? It Might Be Your Gut
The gut-brain connection reveals how food and microbes shape our mental health.
We've all struggled with low mood from time to time. Life has its natural ups and downs, and periods of sadness and grief are completely normal. However, if you have persistent feelings of low mood without any identifiable cause, it might be something is off physiologically. There are several things that can cause our mental health to suffer as it relates to nutrition, including nutrient gaps and inflammation, but the most common one I see in clinical practice is poor gut health.
"How can our gut influence our brain?" you might ask. Though we've been taught that the human body has independent organ systems, in reality everything is interconnected. Our gastrointestinal tract (and the trillions of microbes within it) communicates directly with our brain via the enteric nervous system (ENS). The ENS and the vagal nerve are basically a two-way highway between the gut and brain that is constantly sharing information. You may be familiar with this if you've ever had butterflies in your stomach when you're excited or nervous; your brain is perceiving an important event and telling your gut to get ready!
We all know our gut plays a role in digesting and absorbing our food, but it is also a critical line of defense against foreign and potentially pathogenic invaders entering the body. In fact, it is the home to trillions of bacteria and yeast that are constantly waging battle for the prime real estate of your intestines. Some of these bacteria are beneficial; they produce compounds such as butyrate which helps keep the lining of the intestine strong and healthy. They even produce neurotransmitters like GABA and serotonin which help us to feel calm, relaxed, and content. However, some bacteria are pathogenic; they can damage the intestinal barrier allowing foreign particles to leak through, triggering the immune system. The inflammation that ensues does indeed impact the brain, and clinical research has observed a direction correlation between a disrupted gut microbiome and depression (Kumar et al., 2023).
What's the number one way we can influence the health of our gut and microbiome? What we eat, of course. By prioritizing foods that feed beneficial microbes and avoiding foods that feed pathogenic microbes, we can shift our microbiome into a healthier state. A healthier gut means a healthier brain, and we've set the stage for better mood, energy, and mental clarity. Your gut bugs love fiber, so foods that promote a healthy microbiome include fruits, vegetables, whole grains, legumes, nuts, and seeds. Foods to avoid include processed flours and sugar, so think white bread, pasta, cookies, cakes, candy, soda, etc. These simple carbohydrates feed pathogenic bacteria and yeast that can negatively impact our mental health. Additionally, many processed foods contain additives and preservatives that can disrupt the microbiome. Sticking with whole foods as much as possible is the way to go to support your gut and your brain.
Reference
Kumar, A., Pramanik, J., Goyal, N., Chauhan, D., Sivamaruthi, B. S., Prajapati, B. G., & Chaiyasut, C. (2023). Gut Microbiota in Anxiety and Depression: Unveiling the Relationships and Management Options. Pharmaceuticals (Basel, Switzerland), 16(4), 565. https://doi.org/10.3390/ph16040565