Highlights from

WCD 2019

World Congress of Dermatology

Milan 10-15 June 2019

The role of the gut-skin axis in dermatology, specifically psoriasis

Both the gut and skin are constituents of our barrier against the external environment. Multiple studies showed a connection between gastrointestinal health and skin homeostasis. Recent results from Argentinian researchers demonstrate that there are differences in gut microbiota in non-treated psoriasis patients. However, the cause-effect relationship is still unclear [1].

Gut microbiota is implicated in the maturation of the host immune system and in modulating both the innate and the acquired immune response. Furthermore, gut microbiota is implicated in many fundamental metabolic pathways. An imbalance of gut microbial populations, also called dysbiosis, has been associated with many gastrointestinal diseases and non-intestinal immune-related diseases, like type 1 diabetes, rheumatoid arthritis, and multiple sclerosis. The translocation of bacterial DNA from the intestinal lumen has been described in patients with psoriasis, suggesting that the gut microbiome may play a role in skin diseases.

Differences in gut microbiota

The current study investigated whether there are differences in gut microbiota in non-treated patients with plaque psoriasis (n=55) in comparison with control persons (n=27) without psoriasis, who were matched by sex, age, and body mass index. Psoriasis patients were found to differ from controls with respect to the prevalence of the dominant bacterial phyla. Bacteroidetes were present in 47.1% of psoriasis patients and in 59.9% of controls, while Fimicutes were present in 44.6% of psoriasis patients and in 33.0% of controls. Both differences were statistically significant (P=0.034 and P=0.045, respectively).

Differences between psoriasis severity groups

Furthermore, gut microbiota was compared between psoriasis severity groups. For individuals with moderate-to-severe psoriasis, a weak, but statistically significant tendency was found to carry a less diverse gut microbiome. A systematic and comprehensive evaluation of skin and gut microbiome appraises their interaction with the immune system and composition in diseases. The role of the microbiome in the pathogenesis of psoriasis merits further research.

  1. Ignacio D-C, Florencia G, Alberto P-S. Metagenomic analysis of the human gut microbiome in non-treated plaque psoriasis patients. Poster presented at the World Congress of Dermatology 2019, 10-15 June, Milan, Italy.

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