Effect of acupuncture at Back-Shu points on gut microbiota in insomnia model rats based on metagenomic sequencing technology.

Background: Increasing evidence indicates a bidirectional interaction between the gut microbiota and sleep regulation via the microbiota-gut-brain axis. Acupuncture is widely used to treat insomnia, and its efficacy may be mediated in part by modulation of the gut microbiota and its metabolic pathways. Methods: A rat model of insomnia was established by intraperitoneal injection of para-chlorophenylalanine (PCPA). Rats received acupuncture at Back-Shu points for 2 weeks. Sleep behavior was assessed using the pentobarbital-induced sleep test, and fecal samples were collected for metagenomic sequencing to analyze changes in gut microbial composition and function before and after acupuncture. Results: Compared with the model group, acupuncture significantly shortened sleep latency and prolonged sleep duration. Metagenomic analysis revealed that acupuncture partially restored the PCPA-induced decline in α-diversity and markedly altered β-diversity. Functionally, acupuncture enriched beneficial taxa such as Lactobacillus johnsonii and Ligilactobacillus murinus, and promoted pathways involved in tryptophan and glutamate metabolism as well as short-chain fatty acid (SCFA) synthesis. These changes may act by restoring neurotransmitter balance, strengthening gut barrier integrity, and modulating immune responses. Notably, SCFAs can activate G-protein-coupled receptors to suppress overactivation of the hypothalamic-pituitary-adrenal (HPA) axis, counteracting insomnia-related pathophysiology. Conclusion: Acupuncture at Back-Shu points ameliorates PCPA-induced insomnia-like behavior in rats and beneficially remodels gut microbiota structure and metabolic function. These findings support a key role for the microbiota-gut-brain axis in acupuncture's regulation of sleep and provide a theoretical basis for developing microbiota-targeted adjunctive therapies for insomnia.