Probiotic potential of a high GABA producing strain, Lactobacillus brevis FEM 1874, isolated from traditional “wild” Alpine cheese

In the last years it has been shown how probiotic may potentially impact on neuropsychiatric conditions, by modulating brain functions via the gut:brain axis. γ-aminobutyric acid (GABA) is a major inhibitory neurotransmitter which also works in the periphery through immuno-modulation and regulating adipocyte function. Importantly, GABA is produced in high amounts by certain lactobacilli. In Lactobacillus brevis ATCC 367, GABA production depends on the activity of two genes gadA and gadB, expressed as an operon, regulated by gadR, as well the presence of an antiporter gadC. L. brevis FEM 1874 was isolated from a traditional “wild” fermented Alpine cheese and characterized for putative probiotic traits. This novel strain is bile salt hydrolase (BSH) positive, carries gad genes and is able to produce high levels of GABA in pure culture compared to over 100 other local cheese isolates. We studied this strain in terms of growth on different prebiotic substrates, ability to survive upper gut acid and bile challenges and genetically characterized its GABA production related genes. L. brevis FEM 1874 appears to be a strain with promising probiotic properties and might be an important adjuvant in production of functional dairy products. However, further investigations are needed to assess whether this strain produces GABA within the gastrointestinal tract and how this may impact on host immune system and possibly brain function.