The The Gut–Brain Axis in Consultation–Liaison Psychiatry: a biopsychosocial framework for assessment, formulation and management

The gut–brain axis has become an important conceptual framework for understanding the bidirectional relationship between physical and mental health. Consultation‑Liaison Psychiatry is particularly well positioned to incorporate this emerging evidence into routine clinical practice. This narrative synthesises evidence from liaison psychiatry, psychosomatic medicine, and the literature on disorders of gut–brain interaction (DGBI), and proposes a practical biopsychosocial framework for assessment, formulation, management, and training. We review foundational mechanistic studies, large human cohort data, faecal microbiota transplantation experiments, meta‑analyses of randomised controlled trials, and major reviews published between 2020 and 2026.Communication between the gut and brain is now well recognised, operating through neural, hormonal, immune, and microbial–metabolic pathways.