Objective:To explore the relationship between gut microbiota and giant cell arteritis (GCA), and to identifyits potential therapeutic strategies.Methods:Gut microbiota data were obtained from the MiBioGen consortium genome-wide association study (GWAS), and GCA data were obtained from the FinnGen consortium public GWAS. Causal associations between gut microbiota and GCA were assessed using two-sample Mendelian randomization (MR) analyses, including inverse-variance weighted (IVW), weighted median, MR-Egger regression, simple mode, and weighted mode methods. Heterogeneity and horizontal pleiotropy were evaluated, and false positive results were excluded by using the Benjamini-Hochberg (BH) method of multiple hypothesis testing. All analyses were completed using the TwoSampleMR and MRPRESSO software packages (version 4.3.0) in R language. The analysis of the intestinal flora data, followed by conducting network pharmacology analysis were carried out by Cytoscape 3.9.1 and perform molecular docking verification was performed with AutoDock Vina software.Results:IVW simulations revealed 13 gut microbiota taxa were associated with GCA, of which Lachnospiraceae was significantly negatively associated with GCA risk[nSNP=16, OR(95% CI)=0.32(0.16, 0.63), β=-1.15, Se=0.35, P=0.001, FDR<0.05], and there was no heterogeneity (Cochran′s Q test, Q=13.42, P=0.490) as well as horizontal pleiotropy ( P=0.370). Further literature search and computer simulation docking analysis showed that genistein binds to MMP2 with a binding energy of -43.1 kJ/mol. Conclusion:Lachnospiraceae in the gut microbiota was is negatively associated with GCA, and genistein may be able to regulate the abundance of Lachnospiraceae through the MMP2 target to treat GCA, providing a new therapeutic approach for giant cell arteritis.

Objective:To explore the relationship between gut microbiota and giant cell arteritis (GCA), and to identifyits potential therapeutic strategies.Methods:Gut microbiota data were obtained from the MiBioGen consortium genome-wide association study (GWAS), and GCA data were obtained from the FinnGen consortium public GWAS. Causal associations between gut microbiota and GCA were assessed using two-sample Mendelian randomization (MR) analyses, including inverse-variance weighted (IVW), weighted median, MR-Egger regression, simple mode, and weighted mode methods. Heterogeneity and horizontal pleiotropy were evaluated, and false positive results were excluded by using the Benjamini-Hochberg (BH) method of multiple hypothesis testing. All analyses were completed using the TwoSampleMR and MRPRESSO software packages (version 4.3.0) in R language. The analysis of the intestinal flora data, followed by conducting network pharmacology analysis were carried out by Cytoscape 3.9.1 and perform molecular docking verification was performed with AutoDock Vina software.Results:IVW simulations revealed 13 gut microbiota taxa were associated with GCA, of which Lachnospiraceae was significantly negatively associated with GCA risk[nSNP=16, OR(95% CI)=0.32(0.16, 0.63), β=-1.15, Se=0.35, P=0.001, FDR<0.05], and there was no heterogeneity (Cochran′s Q test, Q=13.42, P=0.490) as well as horizontal pleiotropy ( P=0.370). Further literature search and computer simulation docking analysis showed that genistein binds to MMP2 with a binding energy of -43.1 kJ/mol. Conclusion:Lachnospiraceae in the gut microbiota was is negatively associated with GCA, and genistein may be able to regulate the abundance of Lachnospiraceae through the MMP2 target to treat GCA, providing a new therapeutic approach for giant cell arteritis.