Isolation of γ-Aminobutyric Acid (GABA)-Producing Lactic Acid Bacteria with Anti-Inflammatory Effects from Fermented Foods in Korea

Lactic acid bacteria have become popular because of their ?-aminobutyric acid (GABA)-producing ability. In the present study, we selected four Levilactobacillus brevis strains (MG5552, MG5405, MG5261, and MG5522) with GABA-producing ability from the 33 strains isolated from various fermented foods in South Korea. We evaluated their GABA-producing ability using thin-layer chromatography and determined the GABA levels produced by each strain using an amino acid analyzer. Moreover, we investigated the anti-inflammatory activity of the selected strains, and the results revealed that the cell-free supernatant of the strains decreased nitric oxide (NO), inducible nitric oxide synthase (iNOS) expression, and nuclear factor kappa B (NF-?B) activity in RAW264.7 macrophages. Therefore, these GABA-producing LAB strains can regulate nerve excitement and act as probiotics with anti-inflammatory activity.