Disordered intestinal microbes are associated with the activity of Systemic Lupus Erythematosus.

Intestinal dysbiosis is implicated in Systemic lupus erythematosus (SLE). However, the evidence of gut microbiome changes in SLE is limited, and the association of changed gut microbiome with the activity of SLE, as well as its functional relevance with SLE still remains unknown. Here, we sequenced 16S rRNA amplicon on fecal samples from 40 SLE patients (19 active patients, 21 remissive patients), 20 disease controls (Rheumatoid Arthritis patients), and 22 healthy controls, and investigated the association of functional categories with taxonomic composition by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt). We demonstrated that SLE patients, particularly those active patients, had significant dysbiosis in gut microbiota with reduced bacterial diversity and biased community constitutions. Among the disordered microbiota, the genera Streptococcus , Campylobacter , Veillonella , the species anginosus and dispar , were positively correlated with lupus activity, while the genus Bifidobacterium was negatively associated with disease activity. PICRUSt analysis showed that metabolic pathways were different between SLE and healthy controls, and between active and remissive SLE patients. Moreover, we revealed that a random forest model could distinguish SLE from RA and healthy controls (AUC = 0.792), and another random forest model could well predict the activity of SLE patients (AUC = 0.811). In summary, SLE patients, especially the active patients, show an obvious dysbiosis in gut microbiota and its related metabolic pathways. Among the disordered microflora, 4 genera and 2 species are associated with lupus activity. Furthermore, the random forest models are able to diagnose SLE and predict disease activity. ©2019 The Author(s).