The brain, gut, and bladder health nexus: A conceptual model linking stress and mental health disorders to overactive bladder in women

Objective: A small, but growing literature links stressors and mental health disorders (MHDs) across the life course to overactive bladder (OAB) and urinary incontinence symptoms. Mechanisms by which stressors and MHDs may impact bladder health are not fully understood, limiting novel prevention and treatment efforts. Moreover, potential biopsychosocial mechanisms involving the brain and gut have not been considered in an integrated, comprehensive fashion. Methods: Members of the prevention of lower urinary tract symptoms Research Consortium developed conceptual models to inform research on biopsychosocial mechanisms through which stress and MDHs may impact bladder health among girls and women, focusing on brain and gut physiology. Results: Two conceptual models were developed—one to explain central (brain-based) and peripheral (gut-based) mechanisms linking stressors and MHDs to OAB and bladder health, and one to highlight bidirectional communication between the brain, gut, and bladder. Traumatic events, chronic stressors, and MHDs may lead to a maladaptive stress response, including dysregulated communication and signaling between the brain, gut, and bladder. Gut bacteria produce molecules and metabolites that alter production of neurotransmitters, amino acids, short-chain fatty acids, and inflammatory immune response molecules that mediate communication between the gut and brain. Microbiota signal neurogenesis, microglia maturation, and synaptic pruning; they also calibrate brain–gut–bladder axis communication through neurotransmission and synaptogenesis, potentially influencing bladder symptom development. Life course trajectories of risk may be prevented or interrupted by central and peripheral resources for neuropsychological resilience. Conclusions: Depicted pathways, including brain–gut–bladder communication, have implications for research and development of novel prevention and treatment approaches.