Study Design: Randomized Controlled Trial (RCT)

Author Information

1. Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA
2. Department of Veteran Affairs, Malcom Randall VAMC, Gainesville, Florida, USA
3. Health Sciences, Texas A&M University, College Station, Texas, USA
4. Department of Global Biostatistics and Data Science, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, USA
5. Department of Medicine, University of Texas Medical Branch, Galveston, Texas, USA

1. QiQi Zhou1,2, 
2. Meghan L Verne3, 
3. Jeremy Z Fields1, 
4. John J Lefante4, 
5. Sarpreet Basra1, 
6. Habeeb Salameh5, 
7. G Nicholas Verne1

Background

There is ample evidence from numerous clinical studies, that supports the use of L-glutamine as a dietary supplement to help maintain gut barrier function and strengthening lining, to reduce intestinal permeability and help potentially treat Irritable Bowel Syndrome (IBS). 

More effective treatments are needed for patients with postinfectious, diarrhea-predominant, irritable bowel syndrome (IBS-D). Accordingly, this study conducted a randomized, double-blind, placebo-controlled, 8-week-long trial to assess the efficacy and safety of oral glutamine therapy in patients who developed IBS-D with increased intestinal permeability following an enteric infection.

Methods

Eligible adults were randomized into a glutamine group and administered 15g per day or active placebo (whey protein) group for 8 weeks. The primary goal was a reduction of 50 or more points on the Irritable Bowel Syndrome Severity Scoring System (IBS-SS). Secondary goals included: raw IBS-SS scores, changes in daily bowel movement frequency, stool form (Bristol Stool Scale) and intestinal permeability.

106 of the 115 test subjects were randomly assigned to two groups: Glutamine group (n = 54) receiving 15g of Glutamine per day and the placebo group (n = 52) receiving a placebo, which consisted of 15g of Whey Protein for 8 weeks.

Results

The results were staggering and showed 

80% of Glutamine patients achieved their primary goal with a reduction of 50 or more points on the Irritable Bowel Syndrome Severity Scoring System

Glutamine also significantly reduced daily bowel movement frequency (3 vs. 5) 

Stool Form Measured on the Bristol Stool Scale Scores were reduced from (4 vs. 6.5)

Intestinal permeability was also completely normalized in the Glutamine group, but not the control group 

Conclusions

In patients with IBS-D with intestinal hyperpermeability following an enteric infection, oral dietary glutamine supplements dramatically and safely reduced all major IBS-related endpoints. This study shows that L-Glutamine supplementation can effectively treat and reduce symptoms of IBS such as intestinal permeability, bowel movement frequency, bowel quality and overall quality of life factors.