Background Systemic lupus erythematosus (SLE) is a chronic multiorgan autoimmune disease with high morbidity. The pathogenesis is multifactorial. Gut dysbiosis plays a role in the pathogenesis of systemic lupus erythematosus (SLE). It can cause systemic inflammation.

Methods We conducted a randomized, double-blind, placebo-controlled trial to investigate whether synbiotic supplementation could improve gut microbiota composition and function in patients with SLE.

Results Forty six SLE patients were randomised to two groups: the synbiotic group received synbiotic capsule (Lactobacillus helveticus R0052 60%, Bifidobacterium infantis R0033 20%, Bifidobacterium bifidum R0071 20% and 80 mg fructo-oligosaccharides) for 60 days and placebo group. In the synbiotic-supplemented group, 21 patients completed the intervention. In the placebo group, one was excluded from the final analysis because she needed antibiotic treatment for 33 days. We analysed 16s rRNA microbiome data from 89 faecal samples of the 46 patients. We found increases in the Firmicutes to Bacteroidetes ratio, butyrate metabolism and nitrotoluene degradation after synbiotic supplementation. We also found a decrease in potentially pathogenic species and an increase in beneficial species.

Conclusion Synbiotic supplementation affect the composition and functions of gut microbiota in patients with systemic lupus erythematosus.