Lactobacillus plantarum is a typical beneficial probiotic strain with excellent intestinal colonization ability. In recent years, a large number of clinical trials and animal studies have proven that Lactobacillus plantarum acts as a vital psychobiotic strain to effectively improve sleep quality, shorten sleep latency, and relieve insomnia symptoms. It regulates the gut-brain axis, modulates neurotransmitter secretion, and alleviates stress-induced sleep disorders, exhibiting stable and significant sleep-improving efficacy.
Sleep disorders are closely associated with the imbalance of intestinal microflora and abnormal secretion of central neurotransmitters. Gamma-aminobutyric acid (GABA) and serotonin (5-HT) are core inhibitory neurotransmitters that regulate human sleep rhythm, whose deficiency is the main cause of insomnia, difficulty in falling asleep and shallow sleep. Lactobacillus plantarum can intervene in sleep problems through the gut-brain axis, which has been fully verified in published authoritative studies.
A randomized, double-blind, placebo-controlled clinical trial conducted in 2026 confirmed that Lactobacillus plantarum Lp815 significantly improved the sleep status of patients with sleep disturbance. After 6 weeks of continuous supplementation with 5 billion CFU daily, 77.3% of participants showed more than 4-point improvement in the Insomnia Severity Index, much higher than the 57.8% of the placebo group (p = 0.02). Meanwhile, the urinary GABA level of subjects increased significantly, and anxiety symptoms that affect sleep were effectively relieved, especially in female populations (p < 0.01).
Animal experiments further revealed the underlying mechanism. Related studies have shown that Lactobacillus plantarum P72 can markedly reduce sleep latency and prolong sleep duration in stress-model mice. It significantly up-regulates the expression of GABA, GABAA receptor α1 and 5-HT1A receptor in the brain, repairs neurotransmitter dysfunction caused by stress, and stabilizes the nervous system rhythm. In addition, the strain PS128 has been proven to improve deep sleep quality, reduce cortical excitation and fatigue, and effectively alleviate insomnia caused by chronic stress.
In conclusion, Lactobacillus plantarum improves sleep quality through multiple pathways including regulating gut-brain axis balance, promoting GABA and serotonin secretion, and relieving anxiety stress. With solid clinical and preclinical data support, it is a safe and effective functional strain for improving sleep disorders, with broad application prospects in functional foods and health products.
