Leaky Gut and Dermatological Conditions A Systematic Review of the Clinical Evidence

BACKGROUND Increased intestinal permeability, known as leaky gut syndrome, occurs when the intestinal lining of the gastrointestinal tract has been damaged. The influx of unwanted material in the bloodstream can induce an immune response releasing proinflammatory cytokines that have been thought to be correlated with dermatologic conditions. OBJECTIVE We aimed to evaluate the role of leaky gut in dermatological conditions. METHODS PubMed and Embase were systematically searched through September 2020 for clinical studies that measured intestinal permeability in participants with a dermatological condition. RESULTS We identified 20 studies including participants with dermatitis herpetiformis, atopic dermatitis/eczema, systemic sclerosis, psoriasis, bullous pemphigoid, and pemphigus vulgaris/foliaceus. Atopic dermatitis was the most well studied. Studies utilized a range of measures of intestinal permeability, including sugar excretion tests and serum markers. For all disorders reviewed, except bullous pemphigoid and pemphigus vulgaris/foliaceus, there was evidence of increased intestinal permeability in the disease state compared with controls. LIMITATIONS The range of methodology across clinical studies makes it difficult to draw conclusions across results. In addition, studies tended to be small, and only one study included an intervention to target leaky gut syndrome. CONCLUSIONS We have found preliminary evidence of a relationship between leaky gut and certain dermatological conditions.