Table 1 Differentially enriched gut metabolic modules (GMMs) in OA patients and healthy controls (adjusted the age and BMI by Partial correlation test, P value < 0.05); whole GMMs please refer to Additional file 1: Table S5)

Tryptophan degradation

Healthy Controls < OA patients

Glutamine degradation I

Healthy Controls < OA patients

Tyrosine degradation II

Healthy Controls < OA patients

Propionate production III

Healthy Controls < OA patients

Acetate to acetyl-coa

Healthy Controls < OA patients

Triacylglycerol degradation

OA patients < Healthy Controls

Formate conversion

OA patients < Healthy Controls

Glycerol degradation I

OA patients < Healthy Controls

Bifidobacterium shunt

OA patients < Healthy Controls

Glycerol degradation II

OA patients < Healthy Controls

Pentose phosphate pathway (non-oxidative branch)

OA patients < Healthy Controls

Methionine degradation I

OA patients < Healthy Controls

Homoacetogenesis

OA patients < Healthy Controls

Methionine degradation II

OA patients < Healthy Controls

Methanogenesis from carbon dioxide

OA patients < Healthy Controls

Cysteine biosynthesis/homocysteine degradation

OA patients < Healthy Controls

Acetyl-coa to acetate

OA patients < Healthy Controls

Fructose degradation

OA patients < Healthy Controls

Serine degradation

OA patients < Healthy Controls

Methanogenesis-methyl-com

OA patients < Healthy Controls

Glycolysis (preparatory phase)

OA patients < Healthy Controls

Fucose degradation

OA patients < Healthy Controls

Glutamine degradation II

OA patients < Healthy Controls

Glycolysis (pay-off phase)

OA patients < Healthy Controls

Hydrogen metabolism

OA patients < Healthy Controls