Eczema

Eczema and Leaky Gut: The Gut-Skin Connection Explained

June 26, 2026·12 min read

What Is Leaky Gut and Why Does It Affect Skin?

The intestinal lining is normally a tightly regulated barrier. Specialised proteins called tight junctions seal the gaps between intestinal cells, allowing nutrients through while blocking food antigens, bacteria, and lipopolysaccharides (LPS) from entering the bloodstream. When this barrier becomes more permeable—colloquially called "leaky gut" or increased intestinal permeability—these molecules enter circulation and trigger systemic immune activation. For people genetically prone to atopic conditions, this systemic immune activation frequently manifests as eczema flares.

The Research Linking Gut Permeability and Eczema

Multiple studies have found that infants and adults with eczema show higher intestinal permeability than matched controls. In atopic dermatitis patients, circulating LPS (a bacterial cell wall component that should stay in the gut) is elevated and correlates with eczema severity. Th2-skewed immune responses—the hallmark of atopic disease—both result from and worsen gut permeability, creating a feedback loop. Addressing gut barrier integrity is increasingly recognised as a complementary target in eczema management.

Foods That Damage the Gut Barrier

Highly processed foods: Emulsifiers like carrageenan and polysorbate-80 disrupt the gut's mucus layer in animal studies
Alcohol: Even moderate alcohol intake acutely increases intestinal permeability by disrupting tight junction proteins
Gluten (in sensitive individuals): Activates zonulin release, which opens tight junctions—relevant for celiac disease and non-celiac gluten sensitivity
High-sugar diet: Drives dysbiosis and reduces Akkermansia muciniphila, a key mucus-layer-protective species
NSAIDs (aspirin, ibuprofen): Non-dietary but worth noting as frequent gut-barrier disruptors

Foods That Support Gut Barrier Healing

Fermented foods: Kefir, sauerkraut, and kimchi increase microbial diversity and produce short-chain fatty acids (SCFAs) that strengthen tight junctions
Prebiotic fibre: Feeds Bifidobacterium and Lactobacillus species that produce butyrate—the primary SCFA that maintains intestinal epithelial integrity
Bone broth: Contains collagen precursors (glycine, proline) that support connective tissue in the gut lining; evidence is limited but it is a low-risk addition
Zinc-rich foods: Zinc is essential for tight junction protein synthesis; oysters, pumpkin seeds, and beef are good sources
Omega-3 fatty acids: Reduce gut-barrier inflammation and support microbial diversity
Colourful vegetables: Polyphenols act as prebiotics and directly protect the gut epithelium from oxidative damage

Probiotics for Gut Barrier Repair

Probiotic supplementation—particularly with Lactobacillus rhamnosus GG and Bifidobacterium longum—has been shown to reduce intestinal permeability markers and improve eczema severity in some trials. The evidence is most consistent in infants and children, but emerging data support effects in adults. Probiotic-rich fermented foods achieve similar (if less concentrated) effects with lower cost and fewer risks.

How to Track

Sensio allows you to log both foods and eczema flare severity, letting you identify patterns over weeks. High-processed-food weeks, alcohol-containing weekends, and antibiotic courses are all events that can be logged and correlated with skin outcomes. Gut barrier changes take 2–6 weeks to manifest in eczema severity, so tracking over a minimum of 6–8 weeks gives the most meaningful data.

FAQ

Can you test for leaky gut?

Lactulose-mannitol ratio testing is used in research to measure intestinal permeability, but it is not widely available in clinical practice. Stool zonulin tests are available but have inconsistent reliability. Tracking dietary patterns and skin response is more practically useful for most people.

Is leaky gut a recognised medical diagnosis?

Increased intestinal permeability is a measurable physiological phenomenon in research. "Leaky gut syndrome" as a standalone diagnosis is not accepted in mainstream medicine, but gut permeability as a contributing factor in atopic disease is actively researched and increasingly supported.