Effects of electroacupuncture on gut microbiota in a rat model of urticaria

Objective: Growing evidence suggests a strong link between gut microbiota and the pathogenesis of urticaria, positioning the gut-skin axis as a novel therapeutic target. Despite the efficacy of acupuncture in alleviating urticaria symptoms, the underlying mechanisms remain poorly understood. We investigated the effects of electroacupuncture on gut microbiota in a rat model of urticaria. Methods: Sprague-Dawley rats were randomly divided into three groups: control, model, and electroacupuncture. An urticaria model was established by combining active systemic and passive cutaneous allergic reactions. Electroacupuncture treatment was administered for 7 days, during which the number of scratches, the diameter of skin sensitization blue spots, and degranulation rate of mast cells were recorded. Inflammation in the sensitized skin was assessed using hematoxylin and eosin staining, and the composition of the gut microbiota was analyzed using 16S rRNA gene sequencing. Results: Electroacupuncture significantly reduced the frequency of scratching, the diameter of sensitized blue spots, and the degranulation rate of mast cells in rats. The staining results revealed that electroacupuncture decreased inflammatory cell infiltration and fibrous tissue proliferation in the sensitized skin. The 16S rRNA gene sequencing demonstrated that electroacupuncture adjusted the ratio of Firmicutes to Bacteroidetes. Receiver operating characteristic (ROC) curve analysis identified Parabacteroides johnsonii as a potential biomarker for diagnosing urticaria (AUC = 0.8516, where AUC stands for the area under the curve) and Lactobacillus reuteri and Limosilactobacillus as potential biomarkers for predicting the effectiveness of acupuncture treatment (AUC = 0.8281). Conclusion: Electroacupuncture may alleviate urticaria symptoms by modulating the gut microbiota, providing new theoretical and practical directions for acupuncture treatment of urticaria.