In H. pylori negative functional dyspepsia patients, peripheral blood mononuclear cell mediated release of cytokines IL-1β, IL-10, IL-6, and TNF-α were correlated with intensity of pain and cramps, and also nausea, vomiting and delayed gastric emptying, which can lead to reduced food intake (Liebregts et al., 2011). This evidence concerns the gene IL1B and dyspepsia.