Glutamine
Glutamine is the most abundant amino acid in the body & the primary fuel for enterocytes & immune cells; evidence supports its role in preserving gut barrier integrity under stress & dramatically reducing symptoms in post-infectious irritable bowel syndrome.
Evidence last reviewed: 04 Apr 2026
Evidence supports glutamine's effectiveness in reducing symptoms of post-infectious IBS, with a significant response rate in trials. However, its impact on intestinal permeability is less clear, with a meta-analysis showing no significant benefits across mixed populations.
Post-infectious irritable bowel syndrome (IBS-D) symptom severityAdults with diarrhea-predominant post-infectious IBS · RCTModerate
A randomized placebo-controlled trial (n=106) found 79.6% of the glutamine group versus 5.8% of placebo achieved the primary endpoint (≥50-point reduction in IBS Severity Scoring System), a 14-fold difference; glutamine also reduced bowel movement frequency & improved intestinal permeability measures.
Intestinal permeability in adultsMixed adult populations (athletes, surgical, critical illness) · systematic review and meta-analysis of RCTsLow
Meta-analysis of 10 clinical trials (n=352) found that overall glutamine supplementation did not significantly reduce intestinal permeability, but subgroup analysis showed significant benefit at doses >30 g/day for durations under 2 weeks, suggesting dose-dependent effects.
Forms & usage▾
Take 5–10 grams daily, preferably before or after workouts, in powder or capsule form.