GABA：平和維持神経伝達物質-腸内細菌由来の起源とELISAを用いた唾液バイオマーカー検出

The human body is a highly integrated biological system in which the gut flora wields regulatory control beyond simple digestion. Intestinal bacteria control neuronal and behavioral processes via the gut-brain axis; microbial gamma-aminobutyric acid (GABA) synthesis seems to be an essential controller of sleep and central nervous system activity. Increasing data show that neuroactive substances produced from bacteria influence mental health results, circadian rhythm, and sleep structure.

This review investigates the function of gut-derived GABA in sleep control, the part that particular bacterial taxa play, and the translational value of salivary GABA as a non-invasive indicator. Literature discussing microbial pathways for GABA production, gut-brain signalling mechanisms, food modulation, and ELISA-based salivary GABA determination was reviewed. Important GABA-producing genera including Lactobacillus, Bifidobacterium, and Faecalibacterium prausnitzii were investigated. Available data indicates that gut bacteria may contribute up to thirty percent of systemic GABA; metabolites of gut microbes like butyrate improve GABAergic signalling via epigenetic and receptor-mediated pathways. Diets high in probiotics and fermentable fibre are continuously linked to better sleep quality, less sleep latency, and greater sleep continuity. Using ELISA, salivary GABA levels between 0.1 and 1 µmol/L can be measured and show circadian fluctuation, thereby favoring saliva as a useful substitute for total neurochemical activity.

Salivary GABA is a promising, drug-free biomarker connecting CNS performance, sleep regulation, and gut microbial activity. Its non-invasive character permits extensive clinical and community-based study, therefore supporting longitudinal monitoring of gut-brain interactions. Integration of psychobiotic treatments, AI-guided diet, and point-of-care biosensors may eventually change the stomach to be an organ.