L-Glutamine: A Complete Guide To This Gut-Healing Amino Acid

I often suggest a variety of herbals and supplements to help aid in the process of boosting the immune system and healing leaky gut and other gut issues. Oftentimes, L-glutamine is one of the major supplements that comes up. This common supplement is becoming more popular every day and is found in many leaky gut and gut-healing formulations. So let's talk about L-glutamine supplements and their benefits and side effects.

L-glutamine has a wide variety of functions (many of which we'll learn about later in this article), but one of the most exciting is its ability to help with leaky gut. A recent article explained that glutamine is one of the most commonly found amino acids in the blood and cells and is a preferred source of energy for the cells of the small bowel and other immune cells. The authors also explained that glutamine supplementation can protect the lining of the bowel and help it keep a strong intestinal barrier, in addition to reducing intestinal permeability (i.e., leaky gut), enhancing immune cell function, and boosting the immune system while reducing the inflammatory response1. Another study from 2017 showed that giving a glutamine supplement to athletes2 who compete in the heat could reduce leaky gut, and it may be beneficial to consider supplementation before exercising in order to support gut health.

As I mentioned before, L-glutamine has many benefits. One study showed that taking a glutamine supplement resulted in decreased muscle soreness after eccentric exercise3, and this amino acid also can be used in those getting treatment for head and neck cancer because it reduces the incidence of getting inflammation in the mouth4 and painful swallowing. This allows treatment to continue without added interruptions. In this setting, the glutamine supplement is providing a protective coating to the mouth and esophagus and boosting the healing capacity of the cells. L-glutamine has also shown promise for other conditions, such as:

Fatty liver is one of the most common conditions I see in my office as an integrative gastroenterologist; this is largely due to lifestyle and dietary patterns that most people follow. One of the leading causes of liver disease and need for liver transplantation in this country is fatty liver and nonalcoholic steatohepatitis, also known as NASH. People with this condition may also have blood sugar problems, heart disease, metabolic syndrome, and/or obesity. Data from a recent study demonstrated that taking a glutamine supplement protected mice from the progression of liver disease5 from NASH, and prior literature suggested that glutamine could help prevent the development of NASH altogether.

Another interesting study showed that mice who were given glutamine6 got an immune system boost and had reduced rates of reactivation of herpes infection. This research further supports that glutamine may play a role in contributing to a more robust immune system. Along these lines, a review of the literature on glutamine7 suggested that supplementation reduced the rate of hospital-acquired infections, shortened length of hospital stay, and reduced the rate of in-patient mortality. We should note, however, that many of these studies suggested associations and did not reach statistical significance. Nonetheless, this is still an interesting observation.

Indeed, L-glutamine is an important amino acid when it comes to gut health8! This has much greater implications than just inflammation in the gut and inflammatory bowel disease. We know that over 70 percent of our immune system is in the gut. Therefore, autoimmune conditions—such as Hashimoto's thyroiditis, fibromyalgia, and many others—could potentially be influenced by glutamine supplementation. Certainly, further studies are needed to examine each of these conditions individually to prove or disprove this hypothesis. However, there seems to be good evidence that glutamine supplementation can play a role in reducing leaky gut, which is an underlying process that drives many immune and autoimmune conditions.

L-glutamine is an important amino acid that is essential to our gut and immune health and integrity. It can potentially help with a wide variety of dysfunctions from irritable bowel syndrome with diarrhea to inflammatory bowel disease to supporting your blood sugar regulation, metabolism, liver function, and detoxification capacities. It is often found in formulations that are designed to help treat leaky gut. So it's certainly worth talking to your health care provider about as you go through your gut-healing journey!