Abstract
Background: Interleukin (IL)-4 is a potent anti-inflammatory and Th2-type immunoregulatory cytokine. Helicobacter pylori infection in humans induces a polarized Th1 immune response characterized by increased production of interferon-gamma and absence of IL-4. This study was designed to determine the role of endogenous IL-4 in the host defence against gastric colonization by H. pylori