Abstract: High-altitude sleep disturbance is a common acute high-altitude disease that can trigger physiological discomfort such as acute high-altitude reactions, with a lack of safe and effective preventive medications in clinical practice. Based on the gut-brain axis theory, this study designed and prepared a synbiotics combining Lactobacillus rhamnosus (LGG)-Lycium barbarum polysaccharide (LBP). First, the LGG-LBP synbiotics was prepared and evaluated. The mice were randomly divided into healthy, model, positive control (acetazolamide), LBP, LGG and LGG-LBP synbiotics group. After 7 days of administration, the mouse model of high-altitude sleep disturbance was established, the treating effects were evaluated through sleep duration, behavioral, hemogram test, and the content of tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) in blood. 16S rRNA sequencing was used to analyze the changes of gut microbiota, and the pathological changes of small intestine were observed. The LGG-LBP synbiotics prolonged sleep duration, improved exploratory ability and short-term memory, promoted blood cell recovery. Moreover, LGG-LBP synbiotics enhanced the abundance of probiotics in the gut, and reduced intestinal inflammation. LGG-LBP synbiotics may be a potential prophylactic drug for high-altitude sleep disturbance. The animal operation was approved by the Ethics Committee of the Academy of Military Medical Sciences, Academy of Military Science (Approval number: IACUC-DWZX-2022-511). All experiments were conducted in accordance with relevant guidelines and regulations.