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The Gut Brain Axis

The Gut Brain Axis

You’re probably familiar with some of these phrases.

  • Gut check
  • Gut wrenching
  • Gut feeling
  • Gut reaction
  • Go with your gut
  • Gut Instinct
  • Trust your gut

These common phrases have been around for a long time, because people have long sensed a connection between the gut and the brain. Now that we have a better understanding of the biology behind this connection, it has an official name: the Gut-Brain Axis. In short, the gut talks to the brain and the brain talks to the gut. This cross-talk is impacted by what you eat and your gut microbe population. Gut dysbiosis (imbalance in gut microbe populations) can have a negative impact on digestive function, mood and stress levels.

You’ve probably experienced the Gut-Brain Axis cross talk in action, such as:

  • You’re anxious or upset about something in life, which leads to unpleasant digestive symptoms.
  • You ate something that disagrees with you, or you have an infection that causes intestinal turmoil. Result: you feel distressed or agitated.

These acute problems resolve, once the stress or the infection end. Current research and theories about the gut-brain connection are focused on longer term, chronic effects. For example, anxiety and depression are common in people with irritable bowel syndrome (IBS). But which came first? The anxiety/depression which then impacted gut function? Or did poor food choices impact the gut microbiome. A gut microbe population that is out of balance can cause inflammation and immune dysfunction, which can lead to gut irritability and have a negative affect on brain chemistry.

How do gut microbes influence the Gut-Brain Axis? According to current theories, microbes produce metabolites that act on nerves that connect the gut to the brain. Some components of our food supply appear to be “gut disruptors” — they interfere with gut microbes, causing dysbiosis. If you’ve ever had an intestinal infection, you’ve experienced dysbiosis. In acute situations, it leads to severe symptoms. Chronic dysbiosis can cause less severe, but ongoing symptoms which impact nutrient absorption and quality of life.

When the gut microbiome is dysfunctional, some important metabolites may be missing; others may be excessive. Or microbes themselves could adversely impact the gut lining, leading to inflammation, which itself influences the nerve pathways. Pinpointing specific microbes or food components that have specific effects — good or bad — is clearly very complicated.

Enhance your mood with food

It’s early days for this research. Someday we’ll have enough information to provide actionable diet advice. Even then, enhancing your Gut-Brain Axis communication line isn’t going to be as simple as taking a probiotic supplement or eating one or two “super foods”. Is there anything you can do right now? Based on the information we do have, there are general food choices you can make (or not) to support a healthy conversation between your gut and your brain.

1. Avoid gut disruptors

Artificial Sweeteners. There is increasing evidence that artificial sweeteners impact gut microbe populations. There’s also a link between artificial sweetener consumption and risk for depression. Coincidence?

Ultra processed foods. These by definition are loaded with additives and are frequently stripped of nutrients found in natural whole foods. Not a great choice to encourage healthy gut microbe populations.

Some gut disruptors may be harder to avoid. Bacterial and viral infections can’t always be avoided. Medications could adversely impact gut function, but you may need these medications.

2. Include more whole unprocessed foods

For fiber: vegetables, fruit, legumes and whole grains are loaded with nutrients and a vari:ty of food fiber. Fiber is good for gut microbes, and different types of fiber from a variety of food sources is the best plan.

For probiotics: yogurt, kefir, kimchi, kombucha and other fermented foods. These can help balance and replenish gut microbes.

3. Limit empty calorie foods

This is nothing new, but as a reminder: added sugars and excess alcohol aren’t doing you any favors.

The Gut-Brain Future

I was inspired to write about this topic while listening to a recent webinar on gut health, and also delving into a hefty book on gastrointestinal nutrition. The Take-Away for me so far: someday it may be possible to personalize diets and supplements to facilitate a healthy Gut-Brain connection. That won’t be soon; this is an extremely complicated research problem. Meanwhile you can follow some of the advice above.