Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder involving dysregulation of the microbiota-gut-brain (MGB) axis. Acupuncture effectively alleviates IBS symptoms, yet its underlying mechanisms remain incompletely understood. This review synthesizes current evidence to propose a mechanistic framework by which acupuncture treats IBS through MGB axis modulation. We systematically examine: (1) MGB axis dysfunction in IBS pathophysiology across neural, endocrine, and imm