This study investigated the effects of probiotics combined with quadruple therapy on serum levels of tumour necrosis factor-a (TNF-a), interleukin-6 (IL-6), C-reactive protein (CRP), gastrin (GAS), and motilin (MTL) in patients with Helicobacter pylori (Hp)-positive gastric ulcer (GU). The gene discussed is CRP; the disease is gastric ulcer.