RA	Rheumatoid Arthritis
SCFAs	short-chain fatty acids
Treg cell	regulatory T cell
Th cell	T helper cell
PSA	polysaccharide A
SFB	Segmented Filamentous Bacterium
IL	Interleukin
NORA	new-onset untreated RA
anti-CCP	autoantibodies anticyclic citrullinated peptide
DMARDs	disease modifying anti-rheumatic drugs
ACPAs	anti-citrullinated protein autoantibodies
SAA	serum amyloid A
ATP	adenosine 5′-triphosphate
GM-CSF	granulocyte–macrophage colonystimulating factor
TNF-α	tumor necrosis factor ɑ
VEGF	vascular endothelial growth factor
FLS	fibroblast like synoviocytes
MMP	matrix metalloproteinase
NSAIDs	non-steroidal anti-inflammatory drugs