HP and rheumatoid arthritis: The objectives of this study were to investigate which of the established biomarkers of impaired intestinal damage and permeability (zonulin, LPS) and intestinal inflammation (calprotectin) correlate with pathogenic findings in RA, apart from microbiome analysis, to compare, for the first time, fecal and blood levels of zonulin and calprotectin in patients with RA and determine the diagnostic value of each of these analyses.