Intestinal Microbiota Profiling and Predicted Metabolic Dysregulation in Psoriasis Patients

Objectives: The intestinal microbiota has been known to involve in obesity and host immune response. We aimed to investigate the intestinal microbiota and potential genetic function in relation to clinical presentation in psoriasis patients.

Methods: Faecal microbiota and predicted genetic function inferred from high-throughput 16S ribosomal RNA sequencing were analysed between psoriasis (n = 32) and age-, gender- and body mass index (BMI)-matched non-psoriasis subjects (n = 64), from a referral medical centre. The correlation between altered microbiota and disease activity, arthritis and systemic anti-psoriatic drugs was also investigated.

Results: We observed a distinct faecal microbial community structure in psoriasis patients, with an increased abundance of phylum Firmicutes and decreased abundance of phylum Bacteroidetes, across different subgroup of subjects. Ruminococcus and Megasphaera, of the phylum Firmicutes, were the top-two genera of discriminant abundance in psoriasis. A number of functional genes and metabolic pathways involving bacterial chemotaxis and carbohydrate transport were predicted over-represented, whereas genes related to cobalamin and iron transport were predicted under-represented in faecal microbiota of psoriasis patients.

Conclusions: The distinct faecal microbial composition in psoriasis might be associated with altered transport of carbohydrate, cobalamin and iron, as well as chemotaxis.