What is Glutamine?

ISN orange and blue label glutamine bottle next to a scoop of white powdered glutamine on a black floor with blue specks.

Have you ever wondered what exactly glutamine is and why it is found in a supplement form? We’re going to dive deeper and learn more about this very important amino acid in the body. Read on to learn more about the role of glutamine in the body, the functions of it in the body, and why it is taken in a supplement form. 

Glutamine, as already mentioned above, is a key amino acid that is found in abundance in the human body. What are amino acids again? They are the building blocks of proteins found in our cells and tissues, and they are crucial for cell maintenance, proliferation, and survival. In an article from the MDPI on Nutrients, where most of the background and research for this blog post has been referenced, the authors have stated that the rate of glutamine consumption by immune cells is almost the same or even sometimes greater than the rate of glucose consumption in the body (click here to view this article). And remember, glucose is the source of energy for our cells! The release of glutamine in the human body for availability is controlled mostly by these three metabolic organs: the gut, liver, and skeletal muscles. 

Why is glutamine important for the human body?

Glutamine is the most resourceful amino acid in the body when it comes to one’s metabolism and immune function. Just about every cell in the human body can utilize glutamine as a substrate for many different biosynthetic pathways that regulate cell identity and function. 

Glutamine and Immune System Support

Our immune systems in particular, are most of the time functioning within environments where nutrients may be limited. And glutamine is the main fuel for immune system cells—lymphocytes, neutrophils, and macrophages—which utilize glutamine at very high rates when they are under catabolic conditions, and they as well depend on glutamine for proper function so that they can defend our bodies against predators. High intensity exercise is one of these catabolic conditions where glutamine is needed for fuel. This is why glutamine is used as a nutrition supplement for many athletes who are looking to restore their immune functions. 

Glutamine and Metabolism Support

Under catabolic or hypercatabolic conditions within the body, glutamine is needed for metabolic function. However, the availability of glutamine during this time may not always be high due to the “impairment of homeostasis in the inter-tissue metabolism of amino acids,” stated from the same article that is linked above. If there is a persistent glutamine insufficiency or degradation in these tissues, immunosuppression can result due to the affect this insufficiency plays on metabolic pathways and mechanisms that directly depend on glutamine. This is another reason why glutamine has been implemented as a supplement in many peoples’ lives, especially for those who are immunocompromised. 

Glutamine and Exercise

During catabolic activities, such as extensive exercise, the synthesis of glutamine in the human body does not meet the demand it needs. Skeletal muscles hold the highest rate of glutamine synthesis. Therefore, when they are worked vigorously during exercise, the concentration of glutamine in these skeletal muscles is reduced. When this glutamine concentration is continuously reduced due to the inefficient rate of glutamine synthesis during this time, this reduction of glutamine may also inhibit immune cells and other cells that rely on glutamine for function and growth. More so, a lower concentration of glutamine can negatively affect one’s entire body because of glutamine’s role in providing nitrogen atoms to the fusion of purines, pyrimidines, and amino sugars. 

How do these certain organs control the release of glutamine?

The Gut and Glutamine

The gut is the most substantial site for the consumption of glutamine. The small and large intestines can both break down great amounts of glutamine received from one’s diet or bloodstream. However, this does not change the fact that the consumption of glutamine in the intestines is low due to the high GLS enzyme activity and affinity for glutamine. This certain GLS enzyme activity is so important within the intestinal tissues because it is used to, “maintain the tissue integrity and enable adequate absorption of nutrients, as well as to prevent bacterial translocation into the bloodstream.” Reduced GLS activity has been associated with fasting and malnutrition. This is why glutamine supplements can improve intestinal health, especially in athletes who adhere to certain meal plans. 

Skeletal Muscles and Glutamine

Like mentioned earlier, your skeletal muscles hold the highest rate of glutamine synthesis, making them a fundamental contributor to glutamine metabolism and availability, especially since your skeletal muscles are the largest group of tissues in your body. About 80% of the glutamine found in your body comes from skeletal muscles, and about 40% of this amino acid is released during the fasting state when food has been digested, absorbed, and stored. This fasting state occurs mostly overnight, but also if or when you skip meals during your day. Your skeletal muscles need glutamine in order for the metabolic conditions of the cells in your skeletal muscles to stay stable so that amino acid interconversion of glutamine and alanine can take place within the cells. This plays a role in the recovery of your muscles after they have been worked under extensive catabolic conditions. Your muscles need this glutamine in order to continue synthesizing.

The Liver and Glutamine

Glutamine is important when it comes to generating energy for metabolism and proliferation of hepatocytes in your liver. Your liver serves many functions, one in particular being the metabolism of carbohydrates, lipids, proteins, and drugs. Glutamine helps generate these metabolites in the liver in order to help regulate different activities within the liver. 

Do you need a glutamine supplement?

Are you someone who is immunosuppressed? Or, have you suffered a recent injury or illness? Glutamine supplements could be of use for you because glutamine is super important when it comes to keeping your immune system strong, and infection or injuries hinder your immune system. Although our body is supposed to make enough glutamine already, it could use more of it when stress is added onto the body. Exercising adds extra stress to the body, specifically onto one’s muscles. Therefore, glutamine could be of great use to you if you are looking for reduced muscle fatigue and soreness, as well as quicker muscle recovery. However, as I always say, every human body is different so you will never know if it is going to help you, personally unless you give it a try yourself. 

If you are interested in adding a glutamine supplement into your everyday life, checkout Innovative Sports Nutrition’s glutamine powder here

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