Earlier this year, I wrote about 3 highly effective supplements you might want to consider if you have leaky gut symptoms. One of the 3 supplements I mentioned was L-glutamine. And because leaky gut is a topic that’s not going away and something I’m increasingly helping my functional medicine clients with, I’ll be covering L-glutamine in greater detail. But if you don’t remember what leaky gut is, here’s a quick refresher. 

Leaky Gut Summary

It’s when the tight junctions that are on top of your small intestine lining have too much space in between them. These tight junctions are like the posts on a fence. A well-built fence contains just enough space to let a fresh breeze waft through. But the gaps in between are tight enough in order to keep out animals and crazy neighbors. 

The same is true with your small intestinal cellular lining, which is only one-layer thick. In essence your gut health depends on the equivalent of a paper towel. So if the gaps in between the tight junctions that sit on top of your paper towel barrier in your gut are too wide, here’s what happens. Undigested food, bacteria, viruses and toxins can escape into the bloodstream. This is what’s meant by leaky gut.

The tight junctions should open up a tiny bit to allow nutrients like vitamins and minerals, fatty acids and amino acids through. But because of stress, antibiotics and other medications and other factors, the tight junctions can weaken over time, just like a fence post. 

What is L-Glutamine?

So now that we know what leaky gut is, let’s talk about what L-glutamine is since it’s one of the most popular digestive health supplements. 

OK, so L-glutamine is basically just an amino acid. In fact, glutamine is the most abundant amino acid in the human body. And it’s readily available in all foods that contain protein. 

In the human body, L-glutamine is concentrated in muscle tissue. And this is the reason why decades ago, bodybuilders were the first subset or people to take L-glutamine supplements. While L-glutamine won’t make your biceps look like Popeye’s after eating a few cans of spinach, research shows that it does help aid in recovery. 

But the other major area of the body that L-glutamine likes to hang out in is the endothelial cells of the intestine. Remember the paper-towel, single-layer of cells that have a huge role to play in determining what stays in the intestines and what should remain outside the tube? Well, that’s what the endothelial cells of the intestine are. 

And it just so happens that your endothelial cells in your small intestine rely on L-glutamine as a favorite fuel source. In other words, L-glutamine is to your small intestine cells as chicken wings, pizza and beer is to a college student. 

What Are The Benefits Of L-Glutamine For Gut Health? 

This is why L-glutamine supplements are popular. Even though L-glutamine is the most prevalent amino acid in the human body, we are faced with tons of stress. So that means that we may need to get L-glutamine from supplements. 

But what exactly does L-glutamine do for the gut? Well, by feeding the endothelial cells, it helps fortify the intestinal wall, that single layer of cells I keep talking about. In other words, L-glutamine is like a tool that a general contractor would use to rebuild a fence post. 

Thankfully, your gut has more protection than just that paper-towel single layer. It also has a mucosal barrier surrounding it. And research shows that L-glutamine not only strengthens the intestinal cellular lining, it also preserves the mucosal barrier. 

Also, studies like this one show that L-glutamine not only tightens the spaces in between the junctions and supports the mucus barrier, it also helps prevent bad bacteria from sprouting in the gut. And here’s one more benefit. It also helps make healthy colon lining cells. This is important because the colon, aka the large intestine, can also be leaky. 

It’s also in the colon where beneficial short-chain fatty acids are made. And you can’t have many of those if your colon lining cells are damaged. 

Can You Get Enough L-Glutamine From Food? 

If L-glutamine is the most abundant amino acid in the body, then why do we need to take a supplement? Can’t you just go on a high protein diet, if protein-rich foods are a good source of this amino acid? 

Well, besides the fact that eating a very high protein diet can be taxing to the kidneys, there’s another reason why you may need an L-glutamine supplement. 

And that’s because like I said earlier, stress depletes the small intestine lining’s supply of L-glutamine. In fact, research studies show that people who have surgery have better digestive health outcomes if they take an L-glutamine supplement. 

Another thing to keep in mind is that when you eat food, all the different amino acids sort of compete with each other for digestion. But when you take an L-glutamine supplement, it’s more concentrated.

Best Way To Get The Benefits of L-Glutamine For Gut Health


If you want to try L-glutamine to support your gut health, the best way to take it is under my supervision. I can tell you exactly how much to take, when to take it, what to take it with, and for how long you should take it. I’ll also show you what to look for when choosing a high-quality supplement. 

Learn more about my services here.

Or call me at 402.379.9600 to get started! 

Until next time, 

Jenna Witt, NP