Alterations of gut microbiota for the onset and treatment of psoriasis: A systematic review

Psoriasis is a chronic, recurrent and systemic inflammatory skin disease which is mediated by immunoreaction. Its pathogenesis is multifactorial, and the exact driving factor remains unclear. Recent studies showed that gut microbiota, which maintain immune homeostasis of our bodies, is closely related with occurrence, development and prognosis of psoriasis. The intestinal microbial abundance and diversity in patients with psoriasis have changed significantly, including intestinal microbiota disorders and reduced production of short chain fatty acids (SCFAs), abnormalities in Firmicutes/Bacteroidetes (F/B), etc. Besides, the intestinal microbiota of psoriasis patients has also changed after treatment of systemic drugs, biologics and small molecule chemical drugs, suggesting that the intestinal microbiota may be a potential response-to-treatment biomarker for evaluating treatment effectiveness. Oral probiotics and prebiotics administration as well as fecal microbial transplantation were also reported to benefit well in psoriasis patients. Additionally, we also discussed the microbial changes from the skin and other organs, which regulated both the onset and treatment of psoriasis together with gut microbiota. Herein, we reviewed recent studies on the psoriasis-related microbiota in an attempt to confidently identify the "core" microbiota of psoriatic patients, understand how microbiota influence psoriasis through the gut-skin axis, and explore potential therapeutic strategies for psoriasis.