Associations of gut microbiota with disease development, disease activity, and therapeutic effects in patients with systemic lupus erythematosus.

Altered gut microbiota is linked to systemic lupus erythematosus (SLE), but its association with disease development, disease activity, and post-intervention changes remains unclear. We compared new-onset SLE (NOSLE, n = 25), SLE in remission (RemSLE, n = 30), and healthy controls (HC, n = 30) cross-sectionally and conducted the first longitudinal analysis of NOSLE patients (n = 22) from pre-intervention to remission over 12 months. Significant β-diversity differences were observed in both NOSLE and RemSLE compared to HC, but not between NOSLE and RemSLE. Only four operational taxonomic units (OTUs) were enriched in NOSLE versus HC. However, 26 OTUs, including butyrate-producing bacteria (BPB), were depleted, and seven (including five BPBs) remained depleted in RemSLE compared to HC. OTUs positively and negatively correlated with disease activity were also identified. Longitudinal analysis revealed a reversal of several OTUs altered at onset and an increase in Streptococci, unrelated to the disease. Significant β-diversity differences were observed in patients with anti-SSA or anti-RNP antibodies and those with complement reduction compared to their counterparts. Our study identified gut microbiota alterations, including BPB depletion, in SLE regardless of onset or remission status, bacteria linked to disease activity, and a reversal of disease-associated bacteria along with the enrichment of Streptococci through intervention.