L-Glutamine for Immune Function
Glutamine matters in catabolic illness where plasma levels fall; routine supplementation in healthy people shows no immune benefit.
Overview
Verdict
How It Works
Dosing & Protocol
Typical dose
- Recommended dose
- 0.2-0.5 g/kg/day (roughly 15-30 g/day) of L-glutamine in divided doses in catabolic illness; no established dose for immune support in healthy people
- Expected timeframe
- 1-2 weeks in catabolic illness; no established timeframe otherwise
Protocol
- form
- L-glutamine powder in water, not hot liquid, which degrades it
- duration
- Course-limited to the period of catabolic stress; there is no rationale for indefinite use
- co factor
- Take between meals. Evidence is mixed and depends entirely on the population. Glutamine is the preferred fuel for lymphocytes and enterocytes, and plasma glutamine falls in trauma, burns, sepsis and after major surgery, which is the basis for the claim. Trials in critically ill and surgical patients report fewer infections and shorter hospital stays with supplemental glutamine in some settings, though the large REDOXS trial found higher mortality with high-dose glutamine in multi-organ failure, which tempered enthusiasm considerably. In healthy, well-fed people, plasma glutamine is not limiting and supplementation has not been shown to improve immune function or reduce infections.
- titration
- Increase by 5 g every few days to 15-30 g/day in divided doses; reduce if nausea or bloating occurs
- starting dose
- 5 g dissolved in water twice daily between meals, increasing as tolerated. In the clinical settings where evidence exists, dosing was 0.2-0.5 g/kg/day, often given enterally or intravenously under supervision
Evidence
What the studies say
Glutamine supplementation and gut barrier and mucosal immune function: a systematic review
Perna S, Alalwan TA, Alaali Z +3 more
Glutamine improved intestinal permeability markers in catabolic and stressed patients
Safety
Caveats
Safety ceiling: the REDOXS trial found increased mortality with high-dose glutamine in critically ill patients with multi-organ failure, particularly renal failure - high-dose glutamine in critical illness must be a clinical decision, never self-administration. Glutamine is contraindicated in hepatic encephalopathy and should be avoided in cirrhosis or significant liver disease, since its metabolism generates ammonia. Use caution in renal impairment because of the nitrogen load. Avoid without medical advice with a seizure disorder or on anticonvulsants, given theoretical glutamate effects. Avoid in active cancer without oncology advice, since tumour cells consume glutamine avidly. No safety data in pregnancy or breastfeeding - avoid in both, and in children. Trials have used up to 30 g/day short-term; long-term high-dose safety is not established. Recurrent or unusual infections need medical investigation for an underlying immune deficiency.
Less likely to help if
Medical Disclaimer
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