Have you noticed how some people seem to be able to cope with high amounts of stress, whilst other’s struggle with even the smallest amounts? The measure of your ability to cope with stress is known as ‘stress resilience’ and this may be influenced by the bacterial balance in your gut!
Stress is a necessary part of life. Without stress life would be…well, boring! Think of your ability to respond to stress like a muscle. Too little stress and you become weak. Too much and you can break. Just the right amount and you become stronger. The problem is life doesn’t always deliver ‘just the right amount’ of stress. Take the Covid-19 pandemic for instance.
Your ability to cope with stress can be measured in terms of ‘stress resilience’. The more resilience you have, the more stress you can take on, without sacrificing your physical or mental wellbeing.
Whilst genetic, environmental and psychological factors all play a role in determining your stress resilience, new evidence has emerged highlighting the role of another important key player - the gut microbiome. The relationship between the gut microbiome and the stress response is a 2-way street, with stress affecting the microbiome and vice versa. The communication pathway via which this occurs is referred to as the microbiome-gut-brain-axis.
Let’s explore this further…
Microbiome-gut-brain axis: What is it?
Have you ever felt butterflies in your stomach before a first date?
Perhaps you have lost your appetite before an interview or craved comfort food when your mood was low?
If so, then you have experienced first-hand the direct link between the brain and the gut.
This 2-way pathway allows a constant ‘lively chat’ between the gut, microbes and the brain, using various routes such as the nervous system (including vagus nerve), endocrine and immune systems. As a result of this open line of communication, what impacts one system will often impact the other.
Think of it like a phone conversation with a friend; If one of you is in a bad mood, chances are by the end of that conversation – both of you will be!
This fascinating, synergistic relationship can also be demonstrated by several conditions which present with symptoms in both the brain and the gut, such as mild anxiety and medically diagnosed irritable bowel syndrome, just to name a few[i].
To date, most of the research on this axis has focused on communications directed from the brain to the gut. However, since the surprising discovery that approximately 90% of messages go in the reverse direction, scientists have increasingly turned their attention to the gut microbiome[ii].
How does the gut microbiome affect the brain?
Gut bacteria have been found to influence several psychological processes, including mood, cognitive fatigue and mild anxiety.3 Recent evidence suggests this can be achieved is via the following mechanisms:
Gut as the 2nd brain:
One of the ways gut bacteria may impact brain function is via the production of neuro-active chemicals. For instance, several strains of bacteria have shown to produce significant amounts of ‘GABA’, a neurochemical known for its ability to reduce mild anxiety symptoms.1
The gut-immune-brain link:
The gut microbiome can also affect the brain and mood via the immune system.
Research shows the gut microbiome can affect gut permeability and inflammation, and in turn can have effects on symptoms of mild anxiety. [iii]
Stress less with a healthy microbiome:
A gut microbiome deficient in healthy bacteria may lead to an exaggerated stress response.
A recent study showed that antibiotic-induced, ‘germ-free’ mice had increased stress hormone production when exposed to acute stress. [iv]
Did you know?
Transferring faecal microbiota from one mouse to another, can also lead to the transfer of personality traits such as timidness or boldness! [v]
Mood altering metabolites:
It is not just healthy bacteria but also their metabolites that can support stress resilience.
In a recent human study, bacterial metabolites, known as short chain fatty acids, helped reduce stress hormone production in healthy adult males.[vi]
Stress resilience and a healthy gut microbiome:
Taking care of your gut microbiome can contribute to supporting resilience to stress
At Life-Space we are all about feeling good and ‘stressing less’. Here are a few of our favourite tips to help keep your gut (and brain) happy and healthy:
- Relax with a cup of tea –Green tea offers more than just warmth and comfort; it also contains polyphenols which provide antioxidant protection and modulate gut bacteria.[vii]
- Food for mood – Consuming foods rich in tryptophan (such as cashews, almonds, and walnuts), in combination with antioxidant rich foods (such as green tea), can help to increase amounts of ‘feel good’ neurochemicals in the body. They also make great food for your gut bacteria.[viii]
- Exercise for fun – Exercise doesn’t have to be boring. Go for a forest walk, dance in your living room or play with your dog. Not only does exercise increase your ‘feel good’ hormones, but it also helps to balance your gut microbiome
If seeking specific advice on supporting your stress resilience, talk to your health professional.
[i] Strandwitz P. Neurotransmitter modulation by the gut microbiota. Brain research. 2018 Aug 15;1693:128-33.
[ii] Hadhazy, A. Scientific American. Think twice: How the gut’s “second brain” influences mood and wellbeing. USA. 2010 (cited 27/9/21). Available from: https://www.scientificamerican.com/article/gut-second-brain/
[iii] Bear T, Dalziel J, Coad J, Roy N, Butts C, Gopal P. The Microbiome-Gut-Brain Axis and Resilience to Developing Anxiety or Depression under Stress. Microorganisms. 2021 Apr;9(4):723.
[iv] Huang TT, Lai JB, Du YL, Xu Y, Ruan LM, Hu SH. Current understanding of gut microbiota in mood disorders: an update of human studies. Frontiers in genetics. 2019 Feb 19;10:98.
[v] Johnson KV. Gut microbiome composition and diversity are related to human personality traits. Human Microbiome Journal. 2020 Mar 1;15:100069.)
[vi] Dalile B, Vervliet B, Bergonzelli G, Verbeke K, Van Oudenhove L. Colon-delivered short-chain fatty acids attenuate the cortisol response to psychosocial stress in healthy men: a randomized, placebo-controlled trial. Neuropsychopharmacology. 2020 Dec;45(13):2257-66.
[vii] Singh RK, Chang HW, Yan DI, Lee KM, Ucmak D, Wong K, Abrouk M, Farahnik B, Nakamura M, Zhu TH, Bhutani T. Influence of diet on the gut microbiome and implications for human health. Journal of translational medicine. 2017 Dec;15(1):1-7.
[viii] Strasser B, Gostner JM, Fuchs D. Mood, food, and cognition: role of tryptophan and serotonin. Current Opinion in Clinical Nutrition & Metabolic Care. 2016 Jan 1;19(1):55-61.