No abstract

Objectives: Rheumatoid arthritis (RA) is more common in women, and many reports of sex differences have been reported in various aspects of RA. However, there has been a lack of speci c research on women's gut ora. To assess the association between the gut ora and RA patients, this study combined the microbiome with metabolomics.Methods: Fecal samples from RA patients and healthy controls were collected for 16S rRNA sequencing.Nontargeted liquid chromatography-mass spectrometry was used to detect metabolites in fecal samples. We comprehensively used various analytical methods to reveal changes in intestinal ora and metabolites in female patients.Results: The gut ora of RA patients was signi cantly different from that of healthy women. The abundance of Bacteroides, Megamonas and Oscillospira was higher in RA patients, while the abundance of Prevotella, Gemmiger and Roseburia was lower than that of healthy women. Gemmiger, Bilophila and Odoribacter represented large differences in micro ora between RA and healthy women and could be used as potential microorganisms in the diagnosis. Fatty acid biosynthesis was signi cantly different between RA patients and healthy women in terms of metabolic pathways. There were different degrees of correlation between the gut ora and metabolites. Lys-Phe-Lys and heptadecasphin-4-enine can be used as potential markers for RA diagnosis. There was an extremely signi cant positive correlation between Megamonas, Dialister and rheumatoid factors (RF), which was found for the rst time.Conclusions: These ndings indicated that alterations of these gut microbiome and metabolome may contribute to the diagnosis and treatment of RA patients. Key messagesMicrobes in the patients' guts, including Roseburia, Sutterella and Gemmiger, caused differences from healthy women.Lys-Phe-Lys and heptadecasphing-4-enine had high abundance in patients and can be regarded as potential biomarkers.The intestinal microbiota of patients was positively or negatively correlated with metabolites and laboratory indicators.