Article Text
Abstract
Background and aims Systemic lupus erythematosus (SLE) is the prototypical systemic autoimmune disease, and is characterised by hyperactive immune cells and antibody production. Change in gut microbiota is associated with autoimmune diseases in animal and humans models.We hypothesised that similar changes would be seen in patients with lupus, and may be future therapeutic targets.
Methods 21 patients with SLE and 12 controls with no autoimmune disease were enrolled. Stool samples obtained, homogenised and the cells lysed with 0.1 mm sterile zirconia beads and a bead-beater. The DNA was extracted; V4 region of 16S rRNA gene was amplified using PCR. The purified amplicons were sequenced bi-directionally. High-quality reads with Phred score of ≥20 were obtained by using Quantitative Insights into Microbial Ecology. Chimeric sequences were identified with USEARCH and removed from analysis. Taxonomy was assigned by using a naive Bayes classifier trained with the Greengenes taxonomy.
Results In the SLE patients, Proteobacteria phylum was up regulated. The Lachnospiraceae family was not significantly different based on 16S rRNA sequencing. It was however significantly up regulated on quantitative PCR analysis.
The genera of Blautia, Dorea and, Ruminococcus in the Lachnospiraceae family were also significantly up regulated in the lupus.
The bacterial family of Erysipelotrichaceae was also significantly up regulated.
Rikenellaceae, Odoribacteraceae, Christensenellaceae and Peptococcaceae families were all significantly down regulated in Lupus.
Conclusions There were significant changes in gut microbiota between SLE and the control patients. The findings are similar to those reported in animal and human models with lupus and other autoimmune diseases.