Linking Gut to Skin : the Microbiome and Chronic Inflammatory Diseases

Chronic inflammatory diseases, such as inflammatory bowel disease (IBD) and the IBD-associated skin diseases psoriasis and hidradenitis suppurativa (HS), take a prominent place in modern healthcare. And while our knowledge about the separate diseases is growing, the link between these diseases of the gut and skin, is still underexplored. In this thesis, our aim was to explore the gut-skin axis, focusing on clinical and microbial factors.

The main results in this thesis showed that IBD, in particular Crohn’s disease, might have a more severe disease course and a more severe intestinal microbial dysbiosis when concurrent with a skin disease (psoriasis or HS). In contrast, the skin disease has a mild phenotype. Furthermore, psoriasis patients without IBD show similar intestinal microbial signatures to that of IBD patients, supporting the presence of a microbial gut-skin connection. This was not demonstrated in HS patients.

Additionally the influence of environmental factors (such as medication and UV-exposure) on the microbiome composition were analyzed and future developments in microbial research with emphasis on IBD were discussed.