Multiomic Analysis of the Gut Microbiome in Psoriasis Reveals Distinct Host‒Microbe Associations.

Psoriasis is a chronic, inflammatory skin disease that affects 2‒3% of the global population. Besides skin manifestations, patients with psoriasis have increased susceptibility to a number of comorbidities, including psoriatic arthritis, cardiovascular disease, and inflammatory bowel disease. To understand the systemic component of psoriasis pathogenesis, we performed a pilot study to examine the fecal metagenome, host colonic transcriptome, and host peripheral blood immune profiles of patients with psoriasis and healthy controls. Our study showed increased functional diversity in the gut microbiome of patients with psoriasis. In addition, we identified microbial species that preferentially associate with patients with psoriasis and which have been previously found to associate with other autoimmune diseases. Intriguingly, our data revealed three psoriasis subgroups that have distinct microbial and host features. Integrating these features revealed host‒microbe associations that are specific to psoriasis or particular psoriasis subgroups. Our findings provide insight into the factors that may affect the development of comorbidities in patients with psoriasis and may hold diagnostic potential for early identification of patients with psoriasis at risk for these comorbidities.

The gut microbiome in psoriasis and psoriatic arthritis.

This review summarizes existing research on the gut microbiome composition and function in psoriasis and psoriatic arthritis, exploring potential roles in disease pathogenesis, progression, and management. A strong relationship between skin, joint, and gastrointestinal inflammation exists, as demonstrated by an increased prevalence of psoriasis, psoriatic arthritis, and inflammatory bowel disease co-occurring together; however, the link between them has not been fully elucidated. Studies analyzing the gut microbiome in psoriasis and psoriatic arthritis reveal a unique pattern of dysbiosis. With regard to the gut microbiome's role in psoriasis and psoriatic arthritis pathogenesis, we discuss several theories including intestinal permeability, altered immune homeostasis, and imbalance of short- and medium-chain fatty acid-producing bacteria. We also discuss how the gut microbiome affects patient risk of psoriatic arthritis and other serious comorbidities, and how fecal microbes could be used clinically as therapeutic targets or markers of disease.