Does stress impact your gut health?

2020 has started with a lot of uncertainty for many, as we globally battle a pandemic. These uncertain times can lead to stress and stress can impact your overall health. But how could your gut play a role?

I sat down with Leanne Mitchell, Accredited Practising Dietitian and Microba Microbiome Coach, to discuss …

Deep inside you, there is a collection of bacteria that make up your gut microbiome and influence many areas of health and wellbeing. When you are under stress your body tries to support you by releasing stress hormones.  These hormones flood your body to help you get ready to respond to the “threat”.  This results in many physical changes like sweating, a pounding heart and rapid breathing.  A lot of people also feel stress in their stomach or bowels.  Feelings of nausea, a loss of appetite or an urgent need for the toilet can be experienced by people who are stressed.

But did you know that stress and the associated hormones may also impact your gut microbiome?  Research has shown that even short exposures to stress can shift the types and numbers of bacteria found in the gut¹.  This might help explain why scientists have discovered that people with stress-associated conditions such as depression, have gut microbiomes that are different to healthy people^2,3.

Your gut and your brain speak to each other, and they do this in multiple ways. There is a long nerve that connects the gut and brain called the vagus nerve⁴ and messages run in both directions along this nerve. This nerve is activated by chemical messengers (neurotransmitters) such as serotonin^4,5.  Serotonin levels are associated with mood and wellbeing and special cells in our gut can produce it when stimulated by the short chain fatty acids (SCFAs) butyrate and propionate^5,6.

You can support your gut microbiome’s ability to produce SCFAs by eating a variety of fibre types (called prebiotics) from plant-based foods.  Prebiotics are the food source used by beneficial gut bacteria that produce SCFAs^7,8.   In fact, some of these prebiotic foods, such as barely, bean sprouts and spinach, are also natural sources of another mood-associated neurotransmitter called GABA⁹.  While found in food, our gut bacteria can also produce GABA, but scientists are not yet sure how (or if) this GABA is used in our brains.

Research has shown that certain diets, such as the Mediterranean diet are supportive of mental health^10,11, hinting to a potential role of the gut microbiome in what is now known as the gut-brain axis.

How can you manage stress and keep your microbiome healthy in simple, affordable and home-based ways?

1. Gut-to-brain – fuel your microbiome through healthy eating.
   1. Fill your plate with plenty of prebiotic, plant-based foods such wholegrains, vegetables, legumes, nuts and seeds!
   2. Try going Mediterranean (or meat free) one or two days a week and enjoy large bowls of salad with legumes or roasted capsicum stuffed with zucchini and quinoa or baked fish with roasted vegetables.
2. Brain to Gut strategies – Find time for you… with no commute for many people, why not fill this “extra” time with:
   1. Exercise – find an activity you enjoy or get on YouTube and follow along to a Zumba, circuit, or Pilates classes. You could also make a home gym or go for a run.

Do something that brings you joy – meditate, garden, draw, read or soak in the tub.

For more about your gut microbiome and its links to other areas of the body, see www.microba.com/blog.

Leanne Mitchell is an Accredited Practising Dietitian, Microba Microbiome Coach, PhD candidate and mum of two.

References

1. Hantsoo, L., et al., F160. Cortisol Response to Acute Stress is Associated With Differential Abundance of Taxa in Human Gut Microbiome. Biological Psychiatry, 2018. 83(9, Supplement): p. S300-S301.

2. Anglin, R., et al., The Gut Microbiome in Patients with Anxiety, Depression and Inflammatory Bowel Disease. Neuropsychopharmacology, 2014. 39: p. S289-S289.

3. Winter, G., R. Hart, and C. Sharpley, Gut microbiome and depression: what we know and what we need to know. Reviews in the Neurosciences, 2018. 29(6): p. 629-643.

4. Breit, S., et al., Vagus Nerve as Modulator of the Brain–Gut Axis in Psychiatric and Inflammatory Disorders. Frontiers in Psychiatry, 2018. 9: p. 44.

5. Mohajeri, M.H., et al., Relationship between the gut microbiome and brain function. Nutrition Reviews, 2018. 76(7): p. 481-496.

6. O’Mahony, S.M., et al., Serotonin, tryptophan metabolism and the brain-gut-microbiome axis. Behavioural Brain Research, 2015. 277: p. 32-48.

7. Koh, A., et al., From Dietary Fiber to Host Physiology: Short-Chain Fatty Acids as Key Bacterial Metabolites. Cell, 2016. 165(6): p. 1332-1345.

8. Singh, R.K., et al., Influence of diet on the gut microbiome and implications for human health. J Transl Med, 2017. 15(1): p. 73.

9. Mazzoli R, Pessione E. The Neuro-endocrinological Role of Microbial Glutamate and GABA Signaling.(gamma-aminobutyric acid)(Report). Front Microbiol. 2016;7. doi: 10.3389/fmicb.2016.01934.

10. Sánchez-Villegas, A., et al., Mediterranean dietary pattern and depression: the PREDIMED randomized trial. BMC medicine, 2013. 11: p. 208-208.

11. Opie, R. S., O’Neil, A., Jacka, F. N., Pizzinga, J., & Itsiopoulos, C. (2018). A modified Mediterranean dietary intervention for adults with major depression: Dietary protocol and feasibility data from the SMILES trial. Nutritional Neuroscience, 21(7), 487–501. https://doi.org/10.1080/1028415X.2017.1312841