Stress and the gut microbiota

This year has been extremely challenging and many of us have experienced unprecedented fear and stress, worrying about many things, including health, isolation, financial concerns, job security, and our children’s schooling which all, in turn, affect the health of our gut microbiota.

The stress associated with economic hardship, loneliness and worrying about what tomorrow might bring can be overwhelming. The human body is designed to deal with acute stress through the ‘fight, flight, freeze’ response – when faced with an immediate stressor, we can choose to fight, to run or to do nothing – but we are now faced with chronic daily stress, which can mean we are living in this state continuously.

As the restrictions and changes look set to continue, it can be useful to understand more about stress and how our body, and particularly our gut, reacts to it, to help us to develop strategies to deal with it.

What happens to our body when we are under stress?

Our bodies are well-equipped to deal with life’s stressors by way of a response system that keeps us physically out of harm’s way. When faced with danger, regardless of the stressor (injury, starvation, fear, too hot, too cold or psychological or emotional stress), our body reacts in the same way.

This is known as the general adaptation syndrome (GAS) and has three distinct stages and specific bodily responses at each stage.

1. Alarm reaction stage

This is the ‘fight, flight or freeze’ response that primes us to tackle or move away from the source of stress, or to freeze in some instances. Our body immediately experiences many physiological changes, including:

• quickening in heart rate and blood pressure to push more blood around the body faster to enable more oxygen intake, more blood in the muscles and quicker thinking
• release of stress hormones, adrenaline and cortisol, from the adrenal glands to help increase blood sugar and energy
• inhibition of bodily systems that are unnecessary to deal with the immediate stress, including digestion, reproduction, immunity and excretion

2. Resistance stage

Following the initial stress and the fight-or-flight response, the body begins to repair itself. It remains on high alert for a while, but cortisol release, heart rate and blood pressure all slowly return to normal. If the stress has gone, your body will continue to repair until it returns to a pre-stress state.

If a stressful situation continues for an extended period or the stress is not resolved, our body will remain on high alert and will eventually learn to live at a higher stress level. This means that we continue to release cortisol and blood pressure remains at a higher level than it was previously. You may experience ongoing symptoms of fatigue, irritability and poor concentration.

3. Exhaustion stage

If we experience prolonged or chronic stress, as many of us are experiencing currently, remaining in a state of high alert can drain our physical, emotional and mental resources to the point of exhaustion and potentially illness and disease. Typical symptoms and conditions associated with exhaustion from stress include poor digestive health, heart disease, depression and diabetes.

How does stress impact our gut microbiota health?

We’ve all experienced nervous tension accompanied by butterflies, nausea or stomach cramps if we are frightened or in the run-up to a stressful event. This is part of the stress response we have already described and has both short-term and long-term effects on the function of the gut microbiota.

The longer stress continues, the more the gut microbiota will be influenced in a number of ways, including:

• changes in gut motility – the speed with which food and waste moves through the intestines can both increase or decrease
• increase in feelings in the gut, such as butterflies or stomach ache
• changes in stomach acid production, potentially affecting digestion 
• increase in intestinal permeability via increased inflammation
• negative effects on the ability of the gut to regenerate
• negative effects on the numbers and diversity in the intestinal microbiota

Cortisol, which is released during periods of stress, is an inflammatory compound and, whilst being protective in the short-term, long-term inflammation can cause many negative effects throughout the body, including in the gastrointestinal tract.

Our gut microbiota is also particularly sensitive to emotional or psychological stress as there is constant interaction between the gut and brain via the vagus nerve and chemicals known as neurotransmitters.

Tips for supporting the gut during times of stress

1. Eat right – focus on wholefoods that are rich in nutrients and fill at least half of each plate with vegetables each mealtime. Fruit and vegetables are a great source of prebiotic fibre that allow friendly bacteria to thrive in the gut.
2. Add foods that support digestion, such as bitter green leaves (dandelion, watercress, rocket), fermented foods (sauerkraut, fermented vegetables), digestive enzymes (pineapple, papaya) and digestive herbs (ginger, fennel, mint).
3. Consider supplements to support digestion.
4. Avoid excess sugar and processed ‘fast foods’.
5. Exercise every day – don’t overdo it, but push yourself past your comfort zone to get out of breath.
6. Turn off the television – read books, take walks, watch films (particularly comedies), take up a hobby that you enjoy (gardening, carpentry, cooking).
7. Avoid unhealthy coping mechanisms, such as smoking, drinking alcohol, using drugs, over- or under-eating – they might appear to help in the short term but will cause further problems over the longer term.
8. Introduce relaxation techniques daily – deep breathing, meditation, yoga, walking in nature, sitting in the garden.
9. Talk to others as often as possible – social interaction is a great source of comfort.
10. Sing, dance, run, jump, play games – anything that makes you laugh and brings you joy.

Related articles on stress and gut microbiota:

• Stress and the gut microbiota-brain axis – Behavioural Pharmacology
• Stress & the gut-brain axis: Regulation by the microbiome – Science Direct
• Stress and the gut microbiota-brain axis – NCBI

Want to know more?
ProVen Probiotics aim to provide the best support for both you and your health. If you wish to know more about gut health please do not hesitate to call us on 01639 825107 or alternatively, learn more via our blogs or in-depth ProVen research.

ProVen Probiotics, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, SA12 7DJ. Tel: 01639 825107