Brain-Gut Axis in 2017

“Brain–gut interactions and maintenance factors in pediatric gastroenterological disorders. Recommendations for clinical care.” B Reed-Knight et al. Clinical Practice in Pediatric Psychology, 2017; 5: 93-105.

A summary of this review article by Sharon Berry, PhD, ABPP, Past President, Society of Pediatric Psychology:

This review article describes the brain–gut axis as a means to increase understanding of how biological mechanisms implicated in a range of pediatric GI disorders interact with psychological and contextual factors to maintain GI symptoms and (b) provide practical ways for pediatricians and other healthcare providers to  incorporate a discussion of the brain–gut axis into patient education for pediatric GI disorders.

Biological mechanisms of the brain–gut axis including alterations in pain processing, the stress response system, and gut microbiome activity are reviewed. Psychosocial factors that contribute to or maintain disturbances in the brain–gut axis are discussed with implications for clinical assessment and intervention. The authors assert that a mutual understanding by patients, families, and providers alike of the relevant brain–gut interactions and the biopsychosocial model, in general, will serve as a foundation for successful delivery of and adherence to medical and psychological interventions. Important clinical conclusions include:

  • Early discussion of the brain-gut axis may reduce resistance to integrated behavioral or psychological treatment for pediatric gastroenterological disorders.
  • Sample visual aids and descriptive scripts are available within this review to guide discussions of the brain-gut axis with patients and families for a range of pediatric GI disorders.

My take: This article serves is a useful resource for pediatric psychologists to better understand the ideas of visceral hypersensitivity, stress response, and biological triggers (eg. gut microbiome, infections) for gastrointestinal disorders. Its discussion of biopsychosocial assessment and psychological interventions are helpful for pediatric gastroenterologists to understand the psychological approaches toward treatment.

Related blog posts:

Pain changes brain

For several years, there has been research showing changes in PET scans and functional MRI in association with functional abdominal pain.  A recent article goes a step further showing microstructure  brain changes in patients with chronic pancreatitis (Gut 2011; 60: 1554-62).

This study examined 23 patients with pain due to chronic pancreatitis and 14 controls.  Using a 3T MR scanner, apparent diffusion coefficients (ADC) and ‘fractional anistotropy’ (FA) values were assessed in numerous parts throughout the brain.  This new technology, uses an MRI for diffusion tensor imaging which assesses changes in white and grey matter microstructure not evident with more conventional imaging.  Chronic pancreatitis patients had increased ADC in the amygdala, cingulate cortex, and prefrontal cortex.  In addition, FA values were reduced in the cingulate cortex and secondary sensory cortex.  These areas of the brain with these changes are known to be involved in the processing of visceral pain.  Microstructural changes were correlated to patients’ clinical pain scores.  Some of the changes can be influenced by other factors including alcohol usage, depression, Alzheimer’s or diabetes.

This study echoes findings from others that demonstrate structural reorganization of the brain in association with chronic pain.

Additional references:

  • -Gastroenterology 2010; 139: 1310. n=15 IBS women, 12 controls.  IBS pts have emotional modulation of neural responses to visceral stimuli (eg rectal stimulation) –based on functional MRI studies.
  • -Gastroenterology 2006; 130: 26 & 34. Functional MRI measured in response to barostat show increased sensitivity in pts c IBS. Also, altered 5-HT signaling in IBS-D & IBS-C.
  • -J Pediatr 2001; 139: 838-843. Pts c IBS, RAP more sensitive to visceral perception in rectum and stomach respectively.
  • -Gastroenterology 2005; 128: 1819. Brain response to visceral aversive conditioning –>similar cortical responses between actual and anticipated stimuli.
  • -Cereb Cortex 2010; 20: 1409-19.  Changes in brain anatomy associated with neuropathic pain following spinal cord injury.
  • -J Am Acad Child Adolesc Psychiatry 2010; 49: 173-83.  White matter microstructure changes in adolescents with major depression.