Gut Health & Stress
Stress is something that we often think only impacts our mind. Yet, when we feel anxious, frustrated, overwhelmed or unable to switch off; stress shows up in our body, especially if it’s been going on for a long time (chronic). With chronic stress, we can get so used to it being there that we become numb to it. We just keep on going with our busy lives until it becomes too much to ignore. Our bodies have their own ways of letting us know something is wrong. Gut pain, digestive discomfort, fatigue, inflammation, hormone imbalances …
When stress becomes chronic, digestion ceases to be a priority. Our brain will send messages to move it into survival mode; this mean that basic survival needs, the need to keep us safe, will be prioritised over digestion. Understanding the process of how this happens can be the first step to feeling better.
Your Body Was Designed for Survival
Imagine you are walking through the woods and suddenly encounter danger. Within seconds your brain activates the sympathetic nervous system—your "fight or flight" response, survival mode. Stress hormones such as adrenaline and cortisol are released. Your body is clever, and it instantly diverts resources to help you survive that moment.
Blood is diverted away from your digestive organs towards your muscles, so that you can run away or fight.
Heart rate increases.
Breathing becomes faster.
Digestion slows or even stops temporarily.
The problem is that your body responds in a similar way to modern stressors such as financial worries, relationship difficulties, deadlines, over exercising, eat processed foods, alcohol, social media notifications, poor sleep and emotional stress. Our everyday experiences can leave us stuck in survival mode which is not conducive to gut health or general wellbeing. A healthy nervous system needs to be able to move in and out of different states. From survival mode, into regulation, into rest and digest.
The Gut-Brain Axis
The connection between our brain and gut is well researched. We know that they are constantly communicating with each other, influencing each other. This connection is called the ‘Gut-Brain Axis’ with the Vagus nerve being the primary communication highway. It is a two-way highway, taking message in both directions. What is fascinating is that around 80-90% of the messages travel from the gut to the brain, now who thought it was going to be the other way around?
Another fascinating insight is that the type of bacteria in your gut affects your brain. A healthy gut microbiome leads to improved mood and a healthy brain. Equally, when your gut becomes inflamed or imbalanced, it can influence, how you feel, anxieties and your cognitive function. This ‘Microbiome-Brain’ connection also runs through the Vagus nerve.
How Stress Changes Digestion
1. Reduced Digestive Secretions
Digestion begins long before food reaches the stomach. Simply smelling or seeing food activates saliva production, stomach acid and digestive enzymes. Under stress this process becomes impaired. Reduced stomach acid can contribute to:
bloating
reflux
poor protein digestion
nutrient deficiencies
bacterial overgrowth.
Without adequate digestive enzymes, food isn't broken down efficiently.
2. Slower Stomach Emptying
Stress can delay the movement of food from the stomach into the small intestine. Food remains in the stomach for longer, often causing:
fullness
nausea
reflux
heaviness after meals.
Some people experience the opposite response, where stress accelerates stomach emptying, contributing to diarrhoea.
3. Altered Gut Motility
The muscles lining the digestive tract normally contract in rhythmic waves called peristalsis. Stress disrupts this rhythm. For some people this leads to constipation and for other diarrhoea. Many people experience an unpredictable combination of both, particularly in
4. Changes in the Gut Microbiome
Your digestive tract contains trillions of microorganisms that influence digestion, immune function, hormones, mood and inflammation.
Research shows chronic psychological stress can reduce microbial diversity while encouraging the growth of less beneficial bacteria. This imbalance—known as dysbiosis—has been associated with:
IBS
inflammatory bowel disease
obesity
anxiety
depression.
5. Increased Intestinal Permeability (Leaky Gut)
The intestinal lining acts as a protective barrier. When intact, it allows nutrients to pass into the bloodstream while preventing unwanted substances from entering. Chronic stress may increase intestinal permeability allowing bacterial to stimulate the immune system. This can contribute to chronic low-grade inflammation.
6. Heightened Pain Sensitivity
Stress changes the way the brain processes signals coming from the digestive tract. Normal amounts of gas or stretching within the intestines can feel significantly more painful. This process—called visceral hypersensitivity—is one of the hallmark features of IBS.
Stress Doesn't Just Affect Digestion—It Affects Nutrient Absorption
When digestion becomes compromised, nutrient absorption can also suffer. Poor digestion may reduce the absorption of nutrients such as iron, magnesium, zinc, vitamin B12, calcium and protein which over time can contribute to fatigue, poor immune function, low mood, low energy and hormone imbalances.
The Vagus Nerve: Your Rest and Digest Switch
The vagus nerve is one of the most important regulators of digestion. When activated, it supports:
stomach acid production
digestive enzyme secretion
healthy gut motility
communication between the gut and brain
reduced inflammation.
This is why supporting the parasympathetic ("rest and digest") nervous system can have such a profound effect on digestive health.
Practical Ways to Support Your Digestion
While we cannot eliminate all stress, we can change how our nervous system responds to it. The first step is to slow down and find some space to identify your stressors. Here are some simple evidence-based strategies you can start with:
1. Slow Down Before Meals
Take 5 slow breaths before eating. This small pause helps shift your nervous system towards "rest and digest."
2. Eat Mindfully
Avoid eating whilst driving, scrolling, answering emails, at your desk, rushing around.
3. Prioritise Sleep
Sleep deprivation raises cortisol and alters the gut microbiome. Aim for consistent sleep and wake times where possible.
4. Move Your Body
Gentle movement such as walking, yoga, qigong or stretching helps to regulate the
5. Learn to Regulate Stress
Stress management isn't about removing stress. It’s about learning how to feel it in the body and take steps to shift out of survival mode. This takes time and practise. Some proven techniques to investigate and learn include body scans, breath work, meditations, yoga nidra, time in nature, social connections, counselling or coaching where appropriate.
On a Final Note
Digestive symptoms are rarely "just digestive." Your gut responds to your thoughts, emotions, environment, lifestyle and nervous system every single day. If you've been experiencing persistent bloating, constipation, diarrhoea, reflux or abdominal discomfort, it's worth asking not only "What am I eating?" but also:
How stressed am I?
Am I ever truly switching off?
Do I spend enough time in rest and digest?
Healing the gut isn't simply about removing foods or taking supplements. Often, it's about creating the internal environment where digestion can function as it was designed to.
When you calm your nervous system, you don't just feel calmer—you create the conditions for your digestive system to thrive.
References
Breit, S., Kupferberg, A., Rogler, G., & Hasler, G. (2018). Vagus nerve as modulator of the brain-gut axis in psychiatric and inflammatory disorders. Frontiers in Psychiatry, 9, 44.
Carabotti, M., Scirocco, A., Maselli, M. A., & Severi, C. (2015). The gut-brain axis: Interactions between enteric microbiota, central and enteric nervous systems. Annals of Gastroenterology, 28(2), 203–209.
Cryan, J. F., O'Riordan, K. J., Cowan, C. S. M., et al. (2019). The microbiota-gut-brain axis. Physiological Reviews, 99(4), 1877–2013.
Konturek, P. C., Brzozowski, T., & Konturek, S. J. (2011). Stress and the gut: Pathophysiology, clinical consequences, diagnostic approach and treatment options. Journal of Physiology and Pharmacology, 62(6), 591–599.
Mayer, E. A. (2011). Gut feelings: The emerging biology of gut-brain communication. Nature Reviews Neuroscience, 12, 453–466.
Moloney, R. D., Johnson, A. C., O'Mahony, S. M., et al. (2016). Stress and the microbiota-gut-brain axis in visceral pain. CNS Neuroscience & Therapeutics, 22(2), 102–117.
Sapolsky, R. M. (2004). Why Zebras Don't Get Ulcers (3rd ed.). Henry Holt & Company.
About the Author
Tracey Hooks is a Functional Wellness Practitioner and Nervous System Yoga Teacher at Hooked on Wellness. She helps busy women improve digestive health, balance hormones and calm their nervous systems through evidence-informed nutrition, lifestyle medicine, yoga and coaching. If you'd like personalised support, book a free 20-minute Wellness Reset Call to explore how we can work together.