Alterations of the Skin and Gut Microbiome in Psoriasis and Psoriatic Arthritis

Numerous scientific studies in recent years have shown significant skin and gut dysbiosis among patients with psoriasis. A significant decrease in microbiome alpha-diversity (abundance of different bacterial taxa measured in one sample) as well as beta-diversity (microbial diversity in different samples) was noted in psoriasis skin. It has been proven that the representation of <i>Cutibacterium</i>, <i>Burkholderia</i> spp., and <i>Lactobacilli</i> is decreased and <i>Corynebacterium kroppenstedii</i>, <i>Corynebacterium simulans</i>, <i>Neisseria</i> spp., and <i>Finegoldia</i> spp. increased in the psoriasis skin in comparison to healthy skin. Alterations in the gut microbiome in psoriasis are similar to those observed in patients with inflammatory bowel disease. In those two diseases, the <i>F. prausnitzii</i>, <i>Bifidobacterium</i> spp., <i>Lactobacillus</i> spp., <i>Parabacteroides</i> and <i>Coprobacillus</i> were underrepresented, while the abundance of <i>Salmonella</i> sp., <i>Campylobacter</i> sp., <i>Helicobacter</i> sp., <i>Escherichia coli</i>, <i>Alcaligenes</i> sp., and <i>Mycobacterium</i> sp. was increased. Several research studies provided evidence for the significant influence of psoriasis treatments on the skin and gut microbiome and a positive influence of orally administered probiotics on the course of this dermatosis. Further research is needed to determine the influence of the microbiome on the development of inflammatory skin diseases. The changes in microbiome under psoriasis treatment can serve as a potential biomarker of positive response to the administered therapy.