Cause or effect? Interpreting emerging evidence for dysbiosis in systemic sclerosis

Systemic sclerosis (SSc) is an immune-mediated fibrotic disease affecting skin, lung and gut which are all sites with an established microbiome. Altered microbial flora may occur and contribute to the initiation, progression or severity of disease. However, dysbiosis could also be secondary to the disease or immunosuppressive therapy. Here we consider how lessons could be learned from gastroenterology, a speciality where dysbiosis is strongly implicated in disease mechanism and treatment. This could be highly relevant to molecular pathology of skin in SSc and could drive the inflammatory gene signature observed in some skin biopsies.