Electroacupuncture Alleviates Brain Injury Through Vagus Nerve Activation and Gut Microbiota in a Rat Model of Ischemic Stroke.

BACKGROUND: Emerging evidence implicates gut microbiota dysbiosis in exacerbating stroke pathogenesis via the gut-brain axis, suggesting novel therapeutic targets. While electroacupuncture (EA) demonstrates anti-inflammatory effects through vagus nerve activation, its neuroprotective mechanisms via vagus nerve-microbiota crosstalk remain unexplored. METHODS: Rats with middle cerebral artery occlusion received daily ST36 (Acupoint Zusanli) EA for 1 to 7 days postischemia. Subdiaphragmatic vagotomy and fecal microbiota transplant were implemented to validate pathway specificity. Multimodal assessments included longitudinal neurological scoring, infarct volume, systemic/neuroinflammatory profiling (enzyme-linked immunosorbent assay, immunohistochemistry), intestinal fucosylation dynamics (quantitative polymerase chain reaction, lectin staining), and 16S ribosomal RNA sequencing of gut microbiota. RESULTS: EA significantly improved neurological outcomes and reduced infarct volumes at 3 to 7 days after middle cerebral artery occlusion (versus controls), which was abolished by vagotomy. Mechanistically, EA restored gut barrier integrity through vagus-dependent upregulation of fucosyltransferase 2 (Fut2)-driven epithelial α1,2-fucosylation, enhancing mucin 2+ goblet cell density and tight junction protein expression (ZO-1/occludin/claudin-1). Concurrent microbiota shifts included Lactobacillales/Bacteroidales enrichment (linear discriminant analysis >4.0) and pathobiont suppression, which was reversed by vagotomy. Crucially, fecal microbiota transplant from EA-treated donors replicated neuroprotection in germ-free recipients, achieving 33% infarct reduction and 30% survival improvement (P=0.012), whereas fecal microbiota transplant from vagotomized donors showed no therapeutic benefits. CONCLUSIONS: EA at ST36 produced neuroprotection through activating vagal efferent pathways to orchestrate intestinal mucosal repair via Fut2-mediated fucosylation, which reshape microbial ecosystems and attenuate neuroinflammation. These findings establish a previously unrecognized vagus nerve-gut-brain axis mechanism for stroke recovery, positioning microbiota-directed neuromodulation by EA as a translatable therapeutic strategy.