Can sexual dimorphism in rheumatoid arthritis be attributed to the different abundance of Gardnerella

Rheumatoid arthritis (RA) is a common chronic inflammatory joint disease that can cause recurrent attacks of joint pain and swelling. Progression of RA eventually causes joint destruction, ankylosis and deformity, which are associated with significant increases in socioeconomic costs and burdens.1 2 Epidemiological studies conducted worldwide have shown that women are more likely than men of the same age to develop RA, and that the prevalence increases with age. More importantly, relevant literature indicates that the prevalence of RA continues to increase among women.3 4 In addition, female patients experience more severe joint dysfunction compared with male patients.4 Emerging data clearly demonstrate that women with RA have a significantly worse functional status as measured by instruments such as the 28-joint Disease Activity Score (DAS28), Health Assessment Questionnaire and visual analogue scale.4 5 Consequently, an understanding of the causes of this sexual dimorphism may provide new insights and guidance for the development of interventions intended to reduce the incidence of RA. Previously, this sexual dimorphism of RA has been explained in terms of genes located on the X and Y chromosomes, sex hormones and specific physiological and psychosocial conditions.4 However, the above perspectives were accompanied by corresponding limitations. Notably, most of the relevant literature tended to elaborate from the perspective of sex hormones. Those studies focused on the effects of sex …