A systematic review and meta-analysis of clinical trials on the effects of glutamine supplementation on gut permeability in adults.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized placebo-controlled trials
PubMed 39397201 · doi:10.1007/s00726-024-03420-7
What was done
A systematic review and meta-analysis following PRISMA guidelines searched four databases (PubMed, Scopus, Web of Science, and Google Scholar) through April 2023 for randomized placebo-controlled trials evaluating oral glutamine supplementation on intestinal permeability in adults. Data were pooled using a random-effects model to calculate weighted mean differences (WMD) and 95% confidence intervals (CI), with Cochrane risk-of-bias assessment and subgroup analyses.
What was found
Ten randomized trials published between 1998 and 2014 were included, comprising 352 total participants (mean age 46.52 years; 216 intervention, 212 control). Overall, glutamine supplementation had no significant effect on intestinal permeability (WMD: -0.00, 95% CI: -0.04 to 0.03). Subgroup analysis indicated a small reduction in permeability at doses above 30 g/day (WMD: -0.01, 95% CI: -0.10 to -0.08) and for intervention durations of less than 2 weeks.
Why it matters
Glutamine is widely used to support gut barrier function, but this meta-analysis indicates that standard oral supplementation provides no general benefit for intestinal permeability, with possible effects limited to high doses or short durations.
Limits
The total sample size across 10 trials is very small (352 participants), and patient populations varied widely across different underlying diseases. The abstract contains conflicting dose units (reporting >30 g/day in the results and >30 mg/day in the conclusion) and group participant totals (216 intervention plus 212 control exceeding the stated total of 352). Specific gut permeability measurement methods and adverse events were not detailed in the abstract.
Cited by
- partial Dietary glutamine helps heal and repair the intestinal lining.