P36 Gut dysbiosis in severe plaque psoriasis: findings of a case-control study in southern Brazil

Abstract Background Gut dysbiosis may play a role in immune-mediated diseases. There is a growing interest in understanding microbiome influence in psoriasis. Objectives To study the gut microbiome in patients with severe plaque psoriasis, when compared with individuals without psoriasis. In parallel, to evaluate the differences in the gut microbiome of individuals with psoriasis, with and without psoriatic arthritis. Methods V3/V4 16S rRNA gene sequencing and bioinformatic analyses were performed with the total DNA extracted from the stool samples of 30 patients with severe plaque psoriasis and 30 age, gender and body mass index-matched controls from the same geographic location. Psoriatic Arthritis (PsA) was defined by CASPAR criteria. All patients were seen by a board-certified rheumatologist. We excluded patients with other immunomediated or autoimmune diseases, previously related to gut dysbiosis. Also excluded were patients with neoplasias or a previous history of gastrointestinal bypass. Patients were not in systemic treatment for psoriasis and also had not received antibiotics or probiotics in the past 3 months. Results Sixty individuals were studied. No difference in alpha-diversity was documented between the groups (P > 0.05). Beta-diversity analysis showed different clustering of the gut microbiome in severe plaque psoriasis when compared with controls (P = 0.031). Adjusted differential abundance showed an increased expression of Sutterelacea family (P < 0.05) and Sutterella genus (P < 0.01) in the psoriasis group. When comparing patients with and without joint disease (15 PsO × 15 PsA), it was not possible to document differences in terms of alpha or beta diversity. However, patients with established psoriatic arthritis showed higher expression of the Bacteroidacea family (P = 0.02) and Bacterioides genus (P = 0.02). Conclusions It was possible to demonstrate a different pattern of gut microbiome among those with severe plaque psoriasis, when compared with controls. There was a significantly greater expression of the genus Sutterella among patients, which may represent a sign of dysbiosis related to psoriasis. In parallel, there were no statistically significant differences in alpha and beta diversity between patients with joint disease when compared with those without psoriatic arthritis. However, a hallmark in these patients was the greater expression of the genus Bacterioides, like previous studies. Reduction of Akkermansia and Ruminoccocus, previously related to psoriatic disease, were not verified in our sample. Perhaps due to low reading in both groups. This paper is one of the few Brazilian studies and brings insights into microbiome and psoriasis. Microbiome deserves our attention, especially since it brings different opportunities for intervention, although there are still many key points to be confirmed with prospective studies.