Glutamine for Immune Function
Glutamine is not a reliable immune booster for healthy people, and the evidence is sharply split by who is taking it: in critically ill ICU patients with multi-organ failure it has actually signaled harm, while a modest benefit appears only in a narrow surgical setting. For everyday immune support or preventing colds, the case is weak and unproven.
Why this grade7-layer evidence engine
This claim earns a Weak (C) grade because the human evidence pulls in opposite directions depending on the population, so no single recommendation holds. The most rigorous trial, the REDOXS RCT (PMID 23594003, n=1,223), gave high-dose glutamine to ventilated ICU patients with organ failure and found increased 28-day mortality (32.4% vs 27.2%, OR 1.28); it was stopped early. Two further large ICU trials, SIGNET (PMID 21415104) and the Scandinavian trial (PMID 21658010), showed no benefit on infection or survival, and the ESPEN guideline (PMID 30348463) now advises against routine use in unstable, multi-organ-failure patients.
The signal is not uniformly negative, which is why the grade is weak rather than failing. A Cochrane-style review of perioperative surgery (PMID 25199493, 19 RCTs, n=1,462) found fewer post-op infections (RR 0.65) and shorter stays, but rated the evidence only low-to-moderate. A meta-analysis of inflammatory markers (PMID 34213769) was mixed, with no consistent effect on infections or mortality. The athlete cold-prevention finding (PMID 9007457, RR 0.37) came from a small open-label, self-reported study that later, better-controlled trials never replicated.
Authorities reinforce this caution. The NIH Office of Dietary Supplements states the research does not support glutamine alone for performance, EFSA concluded a cause-and-effect relationship has not been established for immune or gut-defense claims, and the Cleveland Clinic frames any benefit as limited to the severely ill or injured. The FDA approval of glutamine (ENDARI) is only for sickle cell disease and says nothing about general immunity.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.448
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高階證據未達主導 (0 positive vs 1 negative)，由 raw_score 決定
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status