IgG Antibodies Against Common Gut Bacteria Are More Diagnostic for Crohn's Disease Than IgG Against Mannan or Flagellin

INTRODUCTION Antibodies to baker's yeast (mannan) have been widely used to aid in diagnosis of Crohn's disease. Recently, there has been interest in antibodies against a flagellin from Clostridium coccoides subphylum. We hypothesized that reactivity with these antigens is a surrogate marker for a generalized increased IgG response against intestinal microbiota in Crohn's disease. METHODS We compared the diagnostic utility of IgG antibodies...