The Gut–Immune Axis in Psoriasis, Endotoxemia, TH17 Activation, and Clinical Relevance

Emerging evidence implicates the gut–immune axis as a significant contributor to systemic inflammation in psoriasis. Alterations in gut microbiota composition and intestinal barrier integrity influence immune signaling pathways central to disease pathogenesis.

Gut Dysbiosis in Psoriasis

Studies demonstrate reduced microbial diversity in psoriasis patients, including decreased abundance of short-chain fatty acid-producing organisms such as Faecalibacterium prausnitzii¹. These changes impair immune regulation and promote inflammatory signaling.

Endotoxemia and Immune Activation

Increased intestinal permeability allows translocation of lipopolysaccharides into systemic circulation. LPS activates dendritic cells and promotes TH17 differentiation, amplifying IL-17 and IL-23 signaling pathways central to psoriasis².

Clinical observations, including symptom improvement during elemental diets and flare exacerbation with high-fat meals, support the role of endotoxin-driven inflammation in disease activity.

Antibiotics, Microbiome Disruption, and Psoriasis

Antibiotic exposure alters gut microbial ecology and may predispose to dysregulated immune responses. This mechanism may explain paradoxical flares and treatment resistance in some patients with extensive antimicrobial histories³.

Clinical Implications

Targeting gut health may support immune regulation through:

• Restoring microbial diversity
• Supporting intestinal barrier integrity
• Reducing endotoxin burden

These strategies complement biologic and topical therapies by addressing upstream immune drivers.

Clinical Insight

Psoriasis is influenced by immune signaling at mucocutaneous interfaces, including the gut. Gut-driven inflammation represents a modifiable contributor to systemic disease burden.

References

1. Hidalgo-Cantabrana C, et al. Gut microbiota dysbiosis in psoriasis. Br J Dermatol. 2019.
2. Zhu X, Zhu J. CD4 T helper cell subsets and immune disorders. Int J Mol Sci. 2020;21(21):8011.
3. Weigle N, McBane S. Psoriasis. Am Fam Physician. 2013;87(9):626-633.