Abstract/Summary

Rationale Evaluative processing of action outcome is considered crucial for learning and adaptive adjustments of behaviour. Feedback-related negativity (FRN) is an event-related potential elicited by feedback presentation, with implicated neural sources in the anterior cingulate cortex. Bidirectional communications within the brain-gut-microbiota axis modulate cognition and behaviour, and microbial composition has been associated with medial prefrontal cortex function and clinical risk for depression. Objectives The present study aimed to investigate associations between specific gut microbiota and the FRN. Methods Twenty-nine healthy participants completed self-report measures of depression and a Faces and Feedback task during electroencephalography recording. Select implicated microbiota genera were enumerated from stool samples (Clos- tridium, Lactobacillus), along with plasma C-reactive protein (CRP) as an index of systemic inflammation. Results FRN amplitude for positive feedback was positively correlated with microbiota abundance. The relationship between Clostridium and FRN was confirmed by multilevel modelling analysis, controlling for depression and CRP. The latter was positively associated with FRN amplitude. Conclusions Findings suggest that the brain-gut-microbiota-axis may modulate or be modulated by self-monitoring pro- cesses. The current work provides insights into neurophysiological mechanisms underlying reward processing and indicates novel directions for therapeutic interventions, such as those that modulate the gut microbiome.