How Does Stress Affect the Gut Microbiome?

Could stress be overtaking your gut health?

The hectic lifestyles of our modern day has increased the levels of stress, anxiety and depression in our society. And although daily stresses can’t be avoided, constant stress that is not managed can impact our gut health!

Brain to Gut: What happens to our gut when we are stressed?

When we are faced with a stressful situation our “fight or flight” mechanisms are activated. This sends a flood of stress hormones into our bodies. The main stress hormones are cortisol and adrenaline. With these hormones flying around the body, our heart rate and blood pressure increases, so too does our breathing and blood glucose levels. Interestingly, our digestive activity is also decreased or changed. For some, this can mean digestive processes stop (constipation), and for others it results in an urgent emptying of the bowels. Whichever the outcome, it is clear that stress affects digestive function.

But beyond functional changes, stress can also impact the composition and function of the gut microbiome – the community of microorganisms living in our gut. Animal studies have found that stress can make the gut and intestines more permeable (leaky), activating immune and pro-inflammatory responses which trigger additional stress hormones to be released (1).

This may help explain why scientists have found that people with stress-associated conditions, such as depression and anxiety, have gut microbiomes that are different to healthy people (2).

A 2018 review found that depressed people had increased levels of bacteria that are associated with poor health, such as those from the Proteobacteria phylum and the Eggerthella genus, while beneficial bacteria, such as those from the Prevotella, Ruminoccus and Coprococcus genera are decreased compared to healthy controls (3).

the Mediterranean diet is a pattern of eating that is high in prebiotic, plant-based fibres

Gut to Brain: Can supporting our gut microbiome help manage our stress?

Serotonin, a neurotransmitter associated with mood and anxiety disorders, is produced in the gut by enterochromaffin (EC) cells which can be stimulated by the presence of the short chain fatty acids (SCFAs), butyrate and propionate.

SCFAs are anti-inflammatory substances produced by gut bacteria that feed on prebiotic fibres found in plant-based foods. One animal study found that mice treated with SCFAs were able to better tolerate stress, showing fewer signs of anxiety and depression than mice without this treatment (4).

Of course, we are not mice but this research indicates the role diet may play in our ability to manage and respond to stress, a role which is mediated by our gut bacteria!

Many studies have shown a link between diet and the risk for depression, and this could be in part due to the ability of diet to shape and alter the gut microbiome. A diet that continues to have increasing evidence showing benefits for depression is the Mediterranean diet which is a pattern of eating that is high in prebiotic, plant-based fibres.

To find out more about your microbiome diversity and balance which can affect your health, contact me to organise a microbiome test which you can do from your home or office.

In health and love

Deena Jane x