Correlation Analysis between Gut Microbiota and Metabolites in Children with Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune-mediated diffuse connective tissue disease characterized by immune inflammation with an unclear aetiology and pathogenesis. This work profiled the intestinal flora and faecal metabolome of patients with SLE using 16S RNA sequencing and gas chromatography-mass spectrometry (GC-MS). We identified unchanged alpha diversity and partially altered beta diversity of the intestinal flora. Another important finding was the increase in Proteobacteria and Enterobacteriales and the decrease in Ruminococcaceae among SLE patients. For metabolites, amino acids and short-chain fatty acids were enriched when long-chain fatty acids were downregulated in SLE faecal samples. KEGG analysis showed the significance of the protein digestion and absorption pathway, and association analysis revealed the key role of 3-phenylpropanoic acid and Sphingomonas. Sphingomonas were reported to be less abundant in healthy periodontal sites of SLE patients than in those of HCs, indicating transmission of oral species to the gut. This study contributes to the understanding of the pathogenesis of SLE disease from the perspective of intestinal microorganisms, explains the pathogenesis of SLE, and serves as a basis for exploring potential treatments for the disease.

Coffee consumption and the risk of rheumatoid arthritis and systemic lupus erythematosus: a Mendelian randomization study

We aimed to analyze the causal association between coffee consumption and the risk of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We performed a two-sample Mendelian randomization (MR) analysis using the inverse-variance weighted (IVW), MR-Egger regression, and weighted median methods. We used publicly available summary statistics datasets of coffee consumption genome-wide association studies (GWASs) as an exposure variable and RA and SLE GWASs as outcomes. Four single-nucleotide polymorphisms (SNPs) from GWASs of coffee consumption were selected as instrumental variables (IVs) to improve inference: NCARD (rs16868941), POR (rs17685), CYP1A1 (rs2470893), and LAMB4 (rs382140). The IVW method showed a causal association between coffee consumption and RA (beta = 0.770, SE = 0.279, p = 0.006). MR-Egger regression revealed that directional pleiotropy was unlikely to be biasing the result (intercept = - 0.145, p = 0.451). While the MR-Egger analysis showed no causal association between coffee consumption and RA (beta = 2.744, SE = 1.712, p = 0.355), the weighted median approach demonstrated a causal association between coffee consumption and RA (beta = 0.751, SE = 0.348, p = 0.031). However, the associations based on the weighted median analyses after the Bonferroni correction were not significant (adjusted p values = 0.091). The IVW, MR-Egger analysis, and weighted median methods showed no causal association between coffee consumption and SLE risk (beta = 0.594, SE = 0.437, p = 0.209; beta = 3.100, SE = 3.632, p = 0.550; beta = 0.733, SE = 0.567, p = 0.196). MR analysis results do not support causal associations between coffee consumption and the development of RA and SLE.