There were no correlations between IL-4 and IL-10 serum concentrations and the relative expression units of Bacteroides, Bifidobacterium, Clostridium coccoides, Clostridium coccoides-Eubacterium rectale, Clostridium leptum, Lactobacillus, Prevotella, and Roseburia detected in stool samples from RA patients. This evidence concerns the gene IL4 and rheumatoid arthritis.