Glutamine Does Not Decrease Calprotectin in Inflammatory Bowel Disease
Based on the best available evidence, glutamine supplementation does not reduce calprotectin levels or improve inflammatory markers in patients with inflammatory bowel disease, regardless of the route of administration.
Evidence from Systematic Reviews
The most comprehensive and recent evidence comes from a 2021 systematic review that specifically evaluated glutamine supplementation in IBD patients 1. This review found:
- No effect on inflammatory markers: Glutamine supplementation showed no impact on inflammation markers, including calprotectin, in IBD patients 1
- No effect on disease activity: The review found no changes in disease course, intestinal permeability, morphology, or disease activity scores 1
- Route of administration irrelevant: These null findings were consistent across oral (21-30g or 0.5g/kg), enteral (7.87-8.3g/100g), and parenteral (0.3g/kg) routes 1
Guideline Recommendations
ESPEN guidelines explicitly state there is insufficient evidence to recommend glutamine supplementation in IBD:
- For Crohn's disease, only two small randomized trials have compared glutamine-enriched formulas to standard formulas or placebo, and neither demonstrated any clinical benefit 2
- Despite theoretical benefits from animal models showing reduced intestinal damage, human trials have failed to translate these findings into meaningful clinical outcomes 2
- The 2009 ESPEN gastroenterology guidelines concluded there is currently insufficient evidence to recommend glutamine use in CD patients 2
Additional Supporting Evidence
A 2016 Cochrane review reinforced these findings 3:
- Two small RCTs (42 total patients) found no statistically significant differences in clinical remission rates with glutamine supplementation 3
- No changes in intestinal permeability were observed in either study 3
- The review concluded there is insufficient evidence to support glutamine for induction of remission in Crohn's disease 3
Understanding Calprotectin Context
While calprotectin is a validated marker of intestinal inflammation in IBD 4, 5:
- Calprotectin levels can distinguish active inflammation from IBS-like symptoms in IBD patients in remission 4
- Higher calprotectin values are characteristic of inflammatory bowel disease compared to functional disorders 5
- However, glutamine has not been shown to reduce this inflammatory marker in clinical trials 1
Clinical Bottom Line
Do not use glutamine supplementation with the expectation of reducing calprotectin levels or controlling inflammation in IBD patients. The evidence consistently shows no benefit across multiple routes of administration and patient populations 1, 3. The theoretical rationale from animal studies has not translated into human clinical benefit 2, 6.