Is there a link between stress and gut health?

The answer to the above question is a resounding YES. Stress can play a huge part in our gut microbiome – when we are stressed, the autonomic and circulatory systems send distress signals from the brain to the gut. If you think about it from a physical standpoint, how many times have you felt stressed - perhaps you’re about to do something out of your comfort zone, and you suddenly have the urge to go to the toilet? Stress can both delay emptying stomach contents, and also speed up motility, so that you need to go right this second…or we could have a disaster on our hands.

What has bacteria got to do with it?

So if stress has the ability to physically make you go to the toilet, do you think it could affect the types, and balance of bacteria in the gut? The answer is 100% yes. Through the gut-brain axis, stress hormones, inflammation, and autonomic alterations occur which alter the composition of the gut bacteria. The gut brain axis is a two way street, so these changes in bacteria can cause the release of metabolites, toxins, and neurohormones, as well as sending signals back up to the brain that can alter eating behaviour and mood. Some bacterial species actually encourage poor eating habits. Think about how when you are stressed you may overeat, often known as ‘stress-eating’, or on the other end of the spectrum you may just completely lose your appetite. This is all due to the hormonal changes happening in your gut as a result of an external (or internal) stressor. The bacteria are literally telling your brain to eat less or eat more, and when it’s eat more, it’s usually eat more sugar or carbs.

The reasons for these signals is because changes can occur to your gut bacteria that cause an imbalance whereby you may acquire a more dominant species that just loves sugar. This bacterial species will start to tell your brain that they simply must get some yummy sugar right away. I’m sure many of you may have experienced this before… at the first sign of stress, healthy eating goes out the window and you immediately reach for highly processed or sugary food. Your brain chemistry and the way you are thinking is actually being influenced by your gut microbes. Fascinating, right?!

Where’s the evidence?

Just to reiterate how much stress can influence the microbes in your gut, there was a study that took stool samples from students in exam week, and they were found to have fewer of a bacteria called lactobacilli in their stool than they had during the relatively untroubled first days of the term.

When looking into other stress studies we can see more evidence that exposure to stress causes changes to microbiota composition, and chronic psychological stress is reflected highly in microbiome make-up. For example, depression due to a stressful life event is associated with higher Enterobacteriaceae, whereas psychological stress is associated with a reduction in Lactobacilli and an increase in Escherichia coli and Pseudomonas.

Does stress affect conditions like IBS?

When talking about stress and the gut it’s important to touch on the topic of IBS. Irritable Bowel Syndrome is one of the most common gastrointestinal issues, and it is actually highly influenced by stress. Research has shown that IBS patients had an altered microbiome composition and changes to serotonin metabolism, as well as experiencing more IBS episodes after being exposed to psychological stress.

As well as affecting the gut microbiome, stress plays a huge part in the intestinal permeability of your gut. Chronic stress can increase this permeability, causing large (potentially toxic) molecules to slip through into circulation, and cause inflammation – which can lead to inflammatory conditions and symptoms like bloating, cramps, fatigue, food allergies and sensitivities, gas, headaches and joint pain. On top of this, it is your gut wall where the nutrients from your food are absorbed, so if it is damaged, then you may not be absorbing sufficient nutrients which will impact your body from running properly. Have you ever noticed when you’re stressed you may feel more run down or tired, or maybe you suffer from back ache or a headache?

If you feel like the stress in your life is impacting your overall health, a nutritional therapist can support you by taking a holistic approach in addressing your stress response, gut microbiome balance, and offering advice on how to reduce your overall stress levels. Book your free 20 minute nutritional consultation here.