Stress, Body, and Health

Introduction

Trauma is often thought of as a psychological event, but emerging research reveals that its effects extend far beyond the mind. Chronic stress and unresolved trauma can leave deep physiological imprints, influencing immune function, hormonal balance, and particularly, gut health. The gut-brain connection — a key focus in functional medicine — plays a central role in how trauma translates into physical symptoms. Understanding this relationship offers new hope for healing through a whole-person, integrative approach.

The Biology of Trauma: When the Body Keeps the Score

The body’s response to trauma begins in the nervous system. When an individual experiences a traumatic event, the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS) become dysregulated. This leads to chronic activation of the fight-or-flight response and elevated levels of cortisol and adrenaline (van der Kolk, 2014).

Over time, this persistent state of hypervigilance causes “wear and tear” on the body — known as allostatic load — contributing to inflammation, hormonal imbalances, and gastrointestinal dysfunction (McEwen & Gianaros, 2011). The body literally “keeps the score,” storing trauma in cellular and biochemical pathways that affect long-term health.

The Gut-Brain Axis: Trauma’s Impact on Digestive Health

The gut-brain axis is a bidirectional communication network between the gastrointestinal tract and the central nervous system, mediated by the vagus nerve, immune molecules, and the gut microbiome. When the brain experiences trauma or stress, it sends signals that alter gut motility, secretions, and microbial balance (Cryan et al., 2019).

Chronic stress and trauma can lead to:

• Increased intestinal permeability (leaky gut), allowing toxins and bacteria to enter the bloodstream (Kelly et al., 2015)

• Altered microbiome composition, reducing beneficial bacteria like Lactobacillus and Bifidobacterium

• Irritable Bowel Syndrome (IBS) and other functional GI disorders

• Heightened inflammation, due to immune activation from gut barrier dysfunction

Studies have shown that trauma-exposed individuals often exhibit changes in microbiota diversity and composition that correlate with symptoms of anxiety, depression, and chronic pain (Bastiaanssen et al., 2021).

Functional Medicine: Addressing Trauma from the Inside Out

Functional medicine approaches trauma not only as a psychological phenomenon but as a whole-body imbalance. By investigating root causes — from chronic inflammation and gut dysbiosis to hormonal and mitochondrial dysfunction — this model provides a roadmap for integrative healing.

Key strategies include:

1. Restoring Gut Integrity

Functional medicine practitioners often use a “4R” or “5R” protocol:

• Remove triggers (processed foods, infections, environmental toxins)

• Replace digestive enzymes and nutrients

• Reinoculate with beneficial probiotics and prebiotics

• Repair the intestinal lining with nutrients like L-glutamine, zinc carnosine, and omega-3 fatty acids

• Rebalance stress response through lifestyle and mind-body practices

2. Regulating the Stress Response

Interventions such as vagus nerve stimulation, mindfulness meditation, yoga, and somatic therapies help calm the nervous system and restore HPA axis balance. These modalities improve vagal tone, reducing gut inflammation and enhancing digestion (Porges, 2011).

3. Supporting the Microbiome

Dietary interventions — including a diverse, plant-based diet rich in polyphenols — support microbial diversity. Fermented foods and targeted probiotic strains (e.g., Lactobacillus rhamnosus GG) have shown promise in improving mood and reducing stress-related symptoms (Sarkar et al., 2016).

4. Addressing Nutrient Deficiencies

Trauma and chronic stress deplete nutrients like magnesium, B vitamins, and omega-

3 fatty acids, which are critical for neurotransmitter balance and mitochondrial energy production. Functional medicine testing helps identify and correct these imbalances.

A Path Toward Healing

Healing from trauma requires a multidimensional approach that integrates psychological, biological, and lifestyle factors. Functional medicine recognizes that trauma reshapes physiology — particularly the gut — and that true recovery must involve restoring balance in both mind and body.

By identifying root causes and personalizing care, functional medicine offers a comprehensive framework for those suffering from the long-term effects of trauma. Through gut repair, stress regulation, and nervous system support, the body can gradually return to a state of resilience and balance.

References

• Bastiaanssen, T. F. S., Cowan, C. S. M., Claesson, M. J., Dinan, T. G., & Cryan, J. F. (2021). Making Sense of the Microbiome in Psychiatry. International Journal of Neuropsychopharmacology, 24(6), 434–449.

• Cryan, J. F., O’Riordan, K. J., Cowan, C. S., et al. (2019). The Microbiota-Gut-Brain Axis. Physiological Reviews, 99(4), 1877–2013.

• Kelly, J. R., et al. (2015). Breaking Down the Barriers: The Gut Microbiome, Intestinal Permeability, and Stress-Related Psychiatric Disorders. Frontiers in Cellular Neuroscience, 9, 392.

• McEwen, B. S., & Gianaros, P. J. (2011). Stress- and Allostasis-Induced Brain Plasticity. Annual Review of Medicine, 62, 431–445.

• Porges, S. W. (2011). The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation. W.W. Norton.

• Sarkar, A., Lehto, S. M., Harty, S., Dinan, T. G., & Cryan, J. F. (2016). Psychobiotics and the Manipulation of Bacteria–Gut–Brain Signals. Trends in Neurosciences, 39(11), 763–781.

• van der Kolk, B. (2014). The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma. Penguin Books.

Kiara P FNP-C, AFMCP, LMT