A note on 'leaky gut'
'Leaky gut' (increased intestinal permeability) is a real physiological phenomenon studied in certain conditions, but 'leaky gut syndrome' as a stand-alone diagnosis treated by supplements is not established — the marketing outruns the science. Genuine GI conditions deserve a diagnosis, not a 'repair' protocol [1].
The popular ingredients
- L-glutamine is an amino acid that fuels gut cells and is studied in specific clinical settings, but evidence for 'repairing' the gut in healthy people is limited.
- Collagen is marketed for the gut lining with little direct human evidence (it's broken into amino acids during digestion).
- Zinc supports tissue integrity and matters when intake is low.
- Soothing (demulcent) botanicals — slippery elm, marshmallow root, DGL licorice — have traditional use for digestive comfort with modest evidence.
- Probiotics support the microbiome but are strain-specific (see our probiotic guide) [2].
What actually supports gut health
The better-supported foundations: a fiber-rich, varied diet that feeds beneficial bacteria, adequate hydration and sleep, limiting unnecessary antibiotics and NSAIDs where appropriate, and managing stress. For diagnosed conditions (IBD, celiac, IBS), medical treatment is what protects and supports the gut [3].
When to see a clinician
Persistent digestive symptoms, blood in stool, unintended weight loss, or severe pain need evaluation — not a 'gut repair' supplement.
Practical guidance
Be skeptical of 'leaky gut cure' marketing; if trying gut-comfort supplements, treat L-glutamine, collagen, and soothing botanicals as low-evidence experiments; support the gut mainly through fiber, diet, and sleep; correct a zinc shortfall if present; and get persistent or alarm symptoms evaluated.
