Microbiome-Gut-Brain Axis
Plain-English definitions of microbiome research vocabulary — the terms you'll see across articles, testing services, and probiotic claims.
The extended concept of the gut-brain axis that explicitly includes the microbiome as an active participant. Communication occurs through neural pathways (vagus nerve), immune signalling, microbial metabolites, and endocrine routes. Disruption of this axis is implicated in IBS, anxiety, depression, and neurodegenerative conditions.
Related terms
Gut-Brain Axis
The bidirectional communication system between the gastrointestinal tract and the central nervous system, involving neural, hormonal, and immune pathways. The microbiome plays a central role in this communication.
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.