Fingerprints of psychiatric symptoms in the stomach-brain axis

Pioneering research on brain-body interactions has revealed the existence of functional coupling between the rhythmic activity of the stomach and brain. While major breakthroughs support a pivotal role of the gut in psychopathology, the mental health implications of this recently discovered stomach-brain axis are unknown. We hypothesised that stomach-brain coupling in transdiagnostic cortical networks would index individual differences in mental health, in particular with anxiogenic factors. We estimated stomach-brain coupling by combining functional brain imaging with electrogastrography in the largest study to date, involving 199 individuals. To assess a spectrum of psychiatric dimensions, we sampled participants exhibiting a distribution of symptoms from subclinical to clinically significant. We then utilised multivariate prediction techniques to estimate stomach-brain fingerprints indexing these mental health profiles. We observed a robust, cross-validated stomach-brain fingerprint indexing psychiatric symptoms in fronto-parietal control and attention networks. Specifically, deteriorated mental health—characterised by higher levels of anxiety, depression, stress, and fatigue, as well as reduced well-being and quality of life—are associated with stronger stomach-brain connections. Crucially, we controlled for brain connectivity, neural variability, bodily mass, and gastric function, thus this link is specific to the stomach-brain axis. We discovered a unique stomach-brain fingerprint of mental health, highlighting a previously unknown visceral component of psychiatric illness. Understanding the role of disrupted gut-brain mechanisms in mental health can potentially refine diagnostic strategies and lead to new therapeutic interventions seeking to remediate maladaptive connections between the body and mind.