High-dose L-glutamine – intestinal healing & stress resistance from the amino acid kitchen

L-glutamine is more than just an amino acid: It's a key component of intestinal protection, stress regulation, and the immune system. In this article, you'll learn why high-dose L-glutamine of 10–20 g daily can be a real game-changer—especially for irritable bowel syndrome, exhaustion, and chronic stress.

Table of contents

• What is L-glutamine anyway?

• Biochemical effects in the intestines and during stress

• Symptoms of deficiency & areas of application

• Treatment with L-Glutamine – Dosage & Safety

• Prevention & everyday use

• Supplements in comparison

• Study situation & current research

• Conclusion with coaching impulses

• Sources

What is L-glutamine anyway?

L-glutamine is the most abundant free amino acid in blood plasma. Although it can be synthesized by the body, it is considered a conditionally essential amino acid under certain conditions such as stress or illness. It is involved in many key processes:

• Main energy source for intestinal cells (enterocytes)

• Nitrogen transporter in the body

• Precursor of neurotransmitters such as glutamate and GABA

• Supporter of ammonia detoxification

Biochemical effects in the intestines and during stress

🧬 Intestinal barrier & mucosal protection

• Stabilizes the tight junctions of the intestinal mucosa

• Supports the regeneration of damaged enterocytes

• Reduces the risk of leaky gut

⚙️ Stress regulation & cortisol modulation

• Buffer elevated cortisol by stabilizing the HPA axis

• Supports the balance between glutamate and GABA , which can have a calming effect

🛡️ Immune system & anti-inflammatory

• Main fuel for immune cells such as macrophages and lymphocytes

• Promotes the production of IgA in the intestine

• Reduces inflammatory cytokines such as TNF-α and IL-6

Symptoms of deficiency & areas of application

Possible symptoms of glutamine deficiency:

• Irritable bowel syndrome, diarrhea, flatulence

• Lack of motivation and mental exhaustion

• Frequent infections, especially after exercise

• Low stress resistance, nervousness

Areas of application for high-dose intake:

• Intestinal cleansing after antibiotics, surgery or infections

• Stress phases , burnout prevention

• Sports regeneration and immune protection during intensive training

• Autoimmune diseases with intestinal involvement

Treatment with L-Glutamine – Dosage & Safety

✅ Dosage recommendation

• 10–20 g daily , ideally divided into 2–3 portions

• Take on an empty stomach or between meals

⏱️ Intake period

• Short-term (7–14 days) for acute complaints

• Medium-term (4–8 weeks) for chronic stress

⚠️ Safety & Contraindications

• Studies show good tolerance up to 30 g daily

• Caution in case of: severe liver insufficiency , glutamate intolerance , epilepsy

Prevention & everyday use

L-Glutamine can be easily integrated into your daily routine:

• Fasting in the morning for intestinal health

• In the evening for nighttime regeneration

• For stress , combined with Ashwagandha or Magnesium

💡 Tip: Supplementary substances such as zinc , curcumin or butyrate can enhance the effect on the intestines.

Supplements in comparison

Dosage form	Advantages	Disadvantages
powder	Highly dosable, free from additives	Taste, dosage errors
Capsules	Practical, precise dosage	Low dose per capsule
Fermented sources	Better tolerability possible	More expensive
Combination preparations	Additional effects from zinc, B6, etc.	Complexity in effect

Study situation & current research

1. Wischmeyer PE et al. (2010): Glutamine therapy in clinical and intensive care medicine. [PMID: 20616776]

2. Kim MH et al. (2017): Glutamine reduces intestinal permeability in Crohn's disease. [PMID: 28549583]

3. Castell LM & Newsholme EA (2001): Role of glutamine in the immune system. [PMID: 11399405]

4. Legault Z et al. (2015): Glutamine for Athletes – Immune Function & Recovery. [PMID: 26269702]

5. Rohde T et al. (2019): Glutamine and the intestinal barrier – current findings. [DOI: 10.1152/japplphysiol.00165.2019]

   
   

Conclusion with coaching impulses

L-glutamine is a silent hero in the body. It nourishes the gut, strengthens the immune system, and buffers stress. Those who frequently suffer from irritable bowel syndrome, chronic stress, or exercise fatigue have been shown to benefit from 10–20 g of glutamine daily.

🎯 Coaching tip: During the regeneration or reset phase, targeted glutamine phases – combined with bitter substances or curcumin – can effectively support intestinal health.

👉 If you're wondering how your body can better cope with stress, this post about emotional exhaustion in the brain might be just right for you.

Sources

1. Wischmeyer PE, et al. (2010). Clinical applications of L-glutamine: past, present, and future . Current Opinion in Clinical Nutrition and Metabolic Care, 13(5), 541–547. https://pubmed.ncbi.nlm.nih.gov/20616776 ▶️

   Summary: Overview of clinical uses of glutamine in critically ill patients, including mechanisms of action, dosage, and limitations.

2. Kim M.H., et al. (2017). Effects of oral glutamine supplementation on intestinal permeability and inflammatory markers in adults with Crohn's disease . Clinical Nutrition, 36(5), 1286-1292. https://pubmed.ncbi.nlm.nih.gov/28549583 ▶️

   Summary: Placebo-controlled study shows significant improvement of the intestinal barrier in patients with Crohn's disease through oral glutamine administration.

3. Castell LM & Newsholme EA. (2001). The role of glutamine in the immune system and in intestinal function in catabolic states . Nutrition, 17(7-8), 665-669. https://pubmed.ncbi.nlm.nih.gov/11399405 ▶️

   Summary: Glutamine plays an essential role for immune cells and enterocytes in catabolic states such as stress or disease.

4. Legault Z, et al. (2015). Glutamine supplementation and immune function during heavy training in athletes . Journal of the International Society of Sports Nutrition, 12:27. https://pubmed.ncbi.nlm.nih.gov/26269702 ▶️

   Summary: High-intensity training can weaken the immune system – glutamine protects athletes from susceptibility to infections.

5. Rohde T, et al. (2019). Glutamine supplementation and intestinal barrier function . Journal of Applied Physiology, 127(3), 900-907. https://doi.org/10.1152/japplphysiol.00165.2019▶️

   Summary: Current evidence on the role of glutamine in stabilizing the intestinal barrier in clinical and healthy populations.