Legacy AI grade · Sources dated 2026-07-25. Not expert reviewed. Coverage is limited to the listed sources. About the new summary workflow
Glutamine for Gut Permeability ("Leaky Gut")
There is no convincing evidence that glutamine supplements meaningfully reduce intestinal permeability or treat "leaky gut," a condition major clinics do not recognize as a formal diagnosis. The trial data are conflicting, lean on surrogate markers, and even include a high-dose safety signal in critically ill patients.
Why this grade7-layer evidence engine
The strongest evidence works against a clear benefit. A 2024 systematic review and meta-analysis (PMID 39397201) found no statistically significant overall effect of glutamine on intestinal permeability, with a possible reduction only in a small subgroup taking more than 30 g/day. Those measurements relied on surrogate markers (lactulose/mannitol ratio, zonulin) rather than symptoms or clinical outcomes, so their real-world meaning is uncertain.
One positive signal exists but is fragile. A single-center, double-blind RCT in post-infectious IBS-D (PMID 30108163, n=106) reported a large symptom and permeability improvement on 15 g/day. The effect size (79.6% vs 5.8% response) is implausibly large, the study has not been independently replicated, and it covers a specific patient group rather than general consumers. A separate ICU trial (REDOXS, PMID 23594003, n=1,223) found high-dose IV plus enteral glutamine increased 28-day mortality (adjusted OR 1.28), a serious caution against extrapolating to high doses or critically ill people.
Regulators and clinics reinforce the weak, disputed grade. The FDA approves glutamine only as a sickle cell drug, and EFSA rejected gut and permeability claims, finding no established cause-and-effect relationship. Mayo Clinic states 'leaky gut' is not a recognized diagnosis with no validated test, Harvard calls its disease links controversial, and only Cleveland Clinic offers a cautious 'may help' that runs against this consensus, which is why the verdict lands at weak and disputed rather than positive.
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 = 0.412
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 無高階證據可裁決
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 1 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status