gut brain axis (GBA)

• bidirectional communication?

  neural signals go both ways
• gut brain axis ?

  enables communication between bacteria in the gastrointestinal (GI) tract and the brain.
• what systems is the GBA linked to?

  endocrine and immune system
• GBA includes?

  • The CNS
  • Sympathetic NS
  • Parasympathetic NS
  • Enteric NS
  • Vagus nerve
  • Gut mircobiota
  • HPA Axis
• enteric nervous system?

  branch of the autonomic NS, managing functions of the digestive system.
• vagus nerve?

  communicates between the gut and the brain. It runs from the brain stem to the intestines.

  
  

  90% of vagus nerves are afferent (sensory)
• the gut sends info about?

  • Hormones
  • Neurotransmitters
  • Pain
  • Movement in muscles
  • Tension in cells and muscles
• gut microbiota?

  • produce GABA Serotonin & Dopamine
  • indicator of physical and mental health
  • disruption to the microbiota can increase susceptibility to disease
  • can impact cognition, stress, anxiety, depression and social behaviours
• connection between microbiota and brain?

  1. presence of bacteria and chemicals produced by bacteria
  2. neurons in gut tissue detect these changes
  3. information is converted into action potentials
  4. action potentials transmitted to the vagus nerve
  5. vagus nerve transmits information to the brain
  6. signals from the gut are linked to the brain
• stress and microbiota?

  • chronic stress increases risk of illness and disease.
  • prolonged activation of HPA axis leads to increased risk of GI tract disorders that are associated with a decrease in good bacteria (e.g. irritable bowel, coeliacs).