On the gut-brain connection and leaky gut syndrome. Originally published 23 June 2017. Last updated 12 April 2021.
Gut-brain science, and the gut-brain connection, is currently in its infancy.
Listen to Dr. Neal address this topic on Episode 245 & Episode 745 of the podcast Optimal Health Daily.
Research Around the Gut-Brain Connection
I’ll put it another way: the evidence regarding smoking and lung cancer is like Methuselah. It’s been around forever.
Contrast this with the evidence regarding the gut-brain connection.
Have you ever heard a parent tell their child, “Before we had you, you were just a twinkle in our eyes”? Well, the evidence regarding the gut-brain connection is like that: it’s just a twinkle in the eyes of scientists at this point. It’s an interesting concept that hasn’t been fully formed; it’s merely an interesting idea.
Therefore, when I talk about gut-brain science, I often find myself using non-committal phrases like: “we think there’s a connection” or “there may be a link.” These are usually followed by me saying, “So, more research is needed.”
But don’t get me wrong. This gut-brain idea is very interesting. In fact, the idea that the health of our digestive organs may influence the health of the brain has been around for over 100 years. Now that we are starting to find some evidence supporting this idea, it’s gaining momentum.
We already knew that the brain can influence our digestive organs. Think about a time when you were really anxious. Did your stomach start to rumble? It’s very possible that the brain sent signals down the nerves to the gut which triggered that nervous stomach feeling.
The brain may also be able to impact the number and types of good and bad bacteria found in the intestines (the number and types of good and bad bacteria are known as our microbiome). And to complicate things, it’s possible that the microbiome may create neurotransmitters and metabolites that affect the brain. After all, there are many cells lining the intestines.
Listen to Serdar's thoughts on your gut microbiome on Episode 1007 of the podcast Optimal Health Daily.
The Gut and Cells Lining the Intestines
This term is actually a very simplified version of something complex that is happening within the body. The term “gut” is most often referring to the stomach, but really can refer to any part of our abdominal area, and therefore, the gastrointestinal tract – not just the stomach, but the small and large intestines, too. In fact, when we’re talking about a leaky gut, we’re actually really only talking about the small and large intestines.
Leaky gut syndrome is often referred to as “intestinal permeability.” When we look at the intestines under a microscope, we see that the interior lining of the intestines – the part that is exposed to the food you eat – are made up of lots of cells. In the small intestine especially, these cells are packed very closely together so that large molecules can’t get past them.
It kind of reminds of me of a game we used to play as kids called, “Red Rover.” It would go something like this: half of us would stand in a line across one end of the schoolyard. We would form this line by holding each other’s hands, ever so tightly, creating the strongest barrier we could across the width of the field. The other half of the class would stand facing us on the opposite end of the field. The group holding hands creating the barrier would then yell, “Red Rover, Red Rover, send ____ right over.”
The blank is where we would insert the name of someone on the opposite side of the field. When that person’s name was called, they would come running at us at full speed. Their goal was to try and break the oh-so-strong barrier we created by holding each other’s hands.
Imagine our small intestines are like the group holding hands– trying to prevent anyone from making it through their barrier. Now imagine food, viruses, bacteria – anything that can get into our gut– as the kid running full steam ahead at the barrier. Sometimes the kid would get through, other times, they would slam against the barrier and fall flat on their face. Same goes for food, viruses, bacteria, or anything else that can be found in the gut. Any one of these can get through the tight barrier of our small intestine.
Listen to Dr. Neal's thoughts on how to keep a healthy gut on Episode 465 of the podcast Optimal Health Daily.
Symptoms of A Leaky Gut
What’s the big deal? Can’t our bodies just destroy whatever gets past the intestinal barrier? Most of the time, absolutely.
But the side effects of something slipping past the intestinal barrier are not so pleasant:
- gas
- bloating
- constipation and/or diarrhea
- joint or body aches
- brain fog
What we’ve learned is that for some people, their Red Rover barrier isn’t as strong. This could be caused by a number of reasons.
Causes of Leaky Gut Syndrome
Stress can make the gut barrier weaker. So can certain foods, possibly pesticides, and antibiotics. Some strongly believe that gluten is the cause of leaky gut. Others blame dairy. But this is not true. Unless there’s a diagnosed food allergy or suspected food intolerance, most folks don’t need to avoid these. It really depends on the person. Often, it is a mystery.
When it comes to increasing symptoms of leaky gut, the usual suspects include:
- stress
- anxiety
- negative thoughts
- depression
- physical inactivity (such as through a sedentary lifestyle)
Leaky Gut Diet and Treatment
Because of the usual suspects listed above, sometimes the first treatment is stress management and becoming more active.
When it comes to treatment of leaky gut syndrome, I would definitely see a physician to make sure there aren’t any undiagnosed food allergies or intolerances. Once that has been ruled out, following an anti-inflammatory diet would likely be helpful. This would be a diet that is:
Low in:
High in:
- fresh fruits
- vegetables
- legumes
- nuts
- seeds
- herbs and spices (like ginger and turmeric)
The following diet and lifestyle changes can help:
- Fruits, vegetables, legumes, nuts, and seeds are high in fiber and high in poly- and monounsaturated fats which help reduce inflammation throughout the body.
- Increasing omega-3 fat consumption through fish or supplementation (those that are high quality, of course) is also helpful.
- Buying organic produce to help lower pesticide exposure may also be helpful.
- For some, limiting alcohol and caffeine may help as well.
- Maintaining an ideal body weight is also helpful to reduce inflammation.
- Be careful when it comes to using pre- or probiotics. This is because for some with leaky gut, supplementing with these may make you feel worse.
- And again, I must emphasize the importance of watching those stress levels and negative thoughts!
Listen to Dr. Neal address this topic on Episode 245 & Episode 745 of the podcast Optimal Health Daily.
