GABA production is caused by the irreversible decarboxylation
of L-glutamate by the action of the enzyme, glutamic acid
decarboxylase (GAD), which is dependent on the pyridoxal 50-
phosphate molecule or vitamin B6. Numerous studies have
demonstrated the presence of GAD in some lactic acid bacteria and
the resistance of GABA under acidic conditions (Cotter & Hill, 2003).
GABA has demonstrated its ability to induce hypotension in animal
models (Hayakawa et al., 2004), as well as in human intervention
trials (Inoue et al., 2003).