HTR3A and irritable bowel syndrome: 389 Plasma 5-HT is significantly increased during the progression of IBS.65 A combined network analysis based on IBS patients indicated that visceral hypersensitivity is associated with gut microbiota related to the local 5-HT system.390 Long-term exposure to 5-HT enhances its interactions of 5-HT3 and 5-HT4 receptors with cannabinoid signaling, deteriorating the progression of visceral hypersensitivity.391 Gut homeostasis modifiers alleviate abdominal pain by restoring normal levels of 5-HT.392