The Microbiome in Psoriasis and Psoriatic Arthritis: Joints.

The microbiome is a known and established immunomodulator of many inflammatory disorders, including psoriasis and psoriatic arthritis. Microbes co-evolved with their human hosts and provide them with nutritional, metabolic, and immunologic support. An accumulating body of evidence has revealed that psoriatic diseases are characterized by a state of intestinal dysbiosis, which has been linked to a decrease in beneficial commensals and fatty acids. This has been shown in both animal models and human samples, and multiple studies have addressed the physiological and potentially pathogenic role of intestinal and cutaneous microbes in human health and disease. In this review, we discuss state-of-the-art literature in the field of the microbiome in psoriatic diseases that was presented during the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2017 annual meeting, with a special emphasis on synovio-entheseal inflammation. A better understanding of these microbe-host interactions can lead to novel diagnostic and therapeutic targets.