Short chain fatty acids: Microbial metabolites for gut-brain axis signalling.
Level 5 - mechanism / opinion, no new human data
Narrative review of mechanistic pathways with no original empirical data
PubMed 35066114 · doi:10.1016/j.mce.2022.111572
What was done
This narrative review synthesized current mechanistic evidence on how short-chain fatty acids (SCFAs)—principally butyrate, acetate, and propionate derived from bacterial fermentation of dietary fiber—translocate from the gut lumen into systemic circulation, cross the blood-brain barrier, and modulate gut-brain axis signaling.
What was found
The abstract provides no numerical data, effect sizes, or quantitative meta-analytic findings. It summarizes mechanistic pathways through which SCFAs directly and indirectly exert acute and chronic effects on brain structure, physiology, and behavior.
Why it matters
Clarifying the physiological pathways linking microbial metabolites to brain function helps frame future research into psychobiotics and targeted microbiome interventions for neuropsychiatric and neurological disorders.
Limits
The paper is a narrative review without systematic search protocols, risk-of-bias grading, or primary clinical trial data reported in the abstract. Much of the underlying mechanistic framework relies on preclinical and translational models rather than definitive human outcomes.
Cited by
- supports Gut bacteria ferment dietary fiber to produce short-chain fatty acids, which signal to the brain through the vagus nerve and the bloodstream.