The Gut-Brain-Spine Axis: Why Your Digestive Health Affects Your Back
The gut-brain axis is one of the most significant developments in neuroscience research of the past two decades. The understanding that the gut and brain are in continuous bidirectional communication, mediated by the enteric nervous system, the vagus nerve, the immune system and the microbiome, has transformed the understanding of conditions as diverse as depression, anxiety, irritable bowel syndrome and chronic pain.
What is less widely understood is the role of the spine in this axis. The enteric nervous system is connected to the central nervous system through both the vagus nerve and through the thoracolumbar sympathetic fibres that originate in the spinal cord. This means the spinal column is not just a structural support but an active participant in the neural communication between gut and brain.
Shared Neural Pathways
The sympathetic nervous system fibres that regulate gut motility, blood flow and secretion originate in the thoracic and lumbar spinal cord segments between T5 and L2. Dysfunction in these spinal segments can influence the sympathetic innervation of the gut. This pathway helps explain the clinical observation that some patients with IBS or digestive irregularity report improvement in digestive symptoms following chiropractic care, even when care was sought for musculoskeletal complaints.
The Microbiome and Inflammation
Dysbiosis, an altered microbiome composition associated with poor diet, antibiotic use, stress and illness, is associated with increased intestinal permeability and systemic low-grade inflammation. This inflammatory state sensitises nociceptors throughout the body, including in spinal and joint tissues, and is now recognised as a contributing factor to chronic musculoskeletal pain. The bidirectional relationship between stress, gut health and musculoskeletal pain forms a reinforcing cycle that requires addressing multiple points of entry.
Clinical Implications at Clifton Chiro
At Clifton Chiro in Bristol, the whole-person approach considers digestive health as part of the clinical picture for patients with chronic pain. The relationship between gut health, inflammation, autonomic nervous system function and musculoskeletal pain informs the understanding of the patient’s presentation and the selection of treatment approaches.
References
Cryan JF, Dinan TG. Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour. Nature Reviews Neuroscience. 2012.
Bonaz B, Bazin T, Pellissier S. The vagus nerve at the interface of the microbiota-gut-brain axis. Frontiers in Neuroscience. 2018.
Kiecolt-Glaser JK et al. Psychological stress, intestinal permeability, and inflammation. Brain, Behavior, and Immunity. 2018.
