L-Glutamine for Leaky Gut Syndrome

Glutamine is the primary fuel for enterocytes and supports intestinal barrier integrity, with good evidence in critical illness and mucosal injury. For general gut symptoms attributed to leaky gut, evidence is limited and should not replace diagnostic workup.

Overview

Verdict

Mixed evidence

How It Works

Glutamine is the preferred oxidative fuel for enterocytes and colonocytes and supports tight junction integrity. Depletion, as in critical illness and severe stress, compromises the intestinal barrier; supplementation in these settings helps restore barrier function and reduce bacterial translocation.

Dosing & Protocol

Typical dose

Recommended dose: 5-10 g daily is typical for gut support; trials in illness have used up to 30 g daily divided. Reasonable as an adjunct, but should not delay exclusion of coeliac disease, IBD and SIBO.
Expected timeframe: 4-8 weeks for a fair trial in gut symptoms

Protocol

form: Plain L-glutamine powder dissolved in water; capsules require impractical numbers
duration: 8 weeks, then reassess
co factor: Address the drivers of barrier disruption alongside: alcohol, chronic NSAID use, and untreated coeliac disease, IBD or SIBO
titration: Increase to 5 g twice or three times daily over 2 weeks if tolerated; clinical trials in burns and critical illness used up to 30 g daily divided, which is not appropriate for routine self-use
starting dose: 5 g L-glutamine powder once daily between meals

Evidence

What the studies say

Randomised trials show glutamine reduces intestinal permeability and complications in critically ill patients, severe burns and chemotherapy-induced mucosal injury. Evidence in IBS with increased permeability is emerging but inconsistent. For otherwise healthy people with vague gut symptoms, there is no robust trial evidence that glutamine improves the symptoms attributed to leaky gut.

Randomised clinical trial: oral glutamine reduces intestinal permeability and IBS symptoms in postinfectious IBS with diarrhoea

Score: 8/10

2019

rct

n=106

Zhou Q, Verne ML, Fields JZ +4 more

Oral dietary glutamine supplements dramatically reduced all major IBS-related endpoints in patients with IBS-D and increased intestinal permeability.

View source

Glutamine for induction of remission in Crohn's disease (Cochrane review)

Score: 7/10

2016

systematic_review

n=42

Yamamoto T, Shimoyama T, Bamba T

There is no evidence from the available randomised trials that glutamine supplementation is effective for induction of remission in Crohn's disease.

View source

Safety

Caveats

"Leaky gut" is a research concept rather than a formal diagnosis, and most human data come from critical illness, burns and chemotherapy rather than otherwise-well adults. Contraindicated in cirrhosis and hepatic encephalopathy, and in significant renal impairment, because of ammonia load. Not advised in pregnancy. Never let it delay testing for coeliac disease or IBD.

Less likely to help if

People whose symptoms stem from an untreated primary diagnosis — coeliac disease, Crohn's, ulcerative colitis, SIBO or bile acid diarrhoea — will not respond until that is treated.

Medical Disclaimer

The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.

Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.