GABA (Gamma-Aminobutyric Acid)
Plain-English definitions of microbiome research vocabulary — the terms you'll see across articles, testing services, and probiotic claims.
The brain's primary inhibitory neurotransmitter, responsible for reducing neuronal excitability. Several gut bacteria, including Lactobacillus and Bifidobacterium species, produce GABA. Research suggests that microbially produced GABA may influence brain function via the vagus nerve, with implications for anxiety and stress.
Related terms
Vagus Nerve
The longest cranial nerve, connecting the brainstem to the abdomen. It is the primary communication channel of the gut-brain axis, with approximately 80% of its fibres carrying signals from the gut to the brain.
Psychobiotic
A live organism (probiotic) that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness. A term coined by Dinan et al. in 2013.