Reduce Stress by Optimising the Health of Your Gut Microbiome

Posted February 2023
Avocado, Edamame & Chili Oil on Corn Thins slices

Are you one of the many people who live a hectic life full of stress? You are not alone if you answered yes. There are many lifestyle habits which can help to reduce feelings of stress. This includes making sure that you are getting enough sleep and practicing mindfulness exercises like meditation and yoga. A factor which impacts your mood and perceived levels of stress that you may not have thought about is your diet.

New research suggests that including a diet which is rich in plant-based foods which include prebiotic fiber as well as fermented foods may help to reduce perceived levels of stress. Your gut microbiome has a direct link to your brain called the brain-gut-axis. When the health promoting microbes in your gut are well fed with enough and a variety of plant-based foods, they help to keep your brain feeling and functioning at its best.

Researchers investigated the effects of perceived levels of stress on forty-five people aged between eighteen and fifty-nine years. These people initially were eating a diet with inadequate fiber for health. The people recruited in this study were separated into two groups. One group only received basic healthy eating advice based on the food pyramid. The other was given support and guidance on how to eat a ‘psychobiotic’ diet for four weeks duration.

The psychobiotic diet was a high fiber, plant-based diet. This included six to eight servings of vegetables and fruits, five to eight servings of whole grains daily, and two to three servings of fermented food daily. Also, three to four serves of legumes each week.

After four weeks the people following the psychobiotic diet reported feeling less stressed compared to those individuals in the control group. Thirty two percent of people following the psychobiotic diet reported feeling less stressed compared to seventeen percent in the control group. Both groups reported better sleep after the four-week study. Getting adequate and quality sleep impacts your brain function, perception of stress and ability to cope with stress.

Researchers found that following the four weeks there were only small changes in the composition of gut microbes in those following the psychobiotic diet. There were, however, significant changes in the chemicals of forty specific faecal lipids and urinary tryptophan metabolites. When the health promoting microbes eat their fuel sources such as prebiotic fiber, they produce different chemical messages which have different effects on your body. Research suggests these chemicals produced by the gut microbes may help reduce perceived levels of stress.

The exact mechanisms on the role of fermented foods, gut health and stress are still being developed. For example, one study reported fermented foods may increase the diversity of health promoting microbes in your gut. Stay tuned for more exciting research which will provide more insight to how fermented foods have a positive impact on the health of your gut and your health.

While more research is needed and this study does have limitations such as the duration of the study and the number of participants, the findings are promising. Lifestyle habits which you can add to help promote gut health and may improve your mental health and reduce the perception of stress, is to structure your diet to be largely plant based. This includes including whole grains, or whole grain containing foods such as Corn Thins slices, nuts, seeds, legumes, beans, fruits, vegetables, as well as enjoying fermented foods daily. Your gut microbiome each need different types of prebiotic fuel to stay alive which is why aiming to include thirty different plant-based foods a week is a smart goal to aim for.

Take home message: There are many different lifestyle habits which can help you to deal with stress. If you have not considered the role of your gut this could be the key factor missing in your ability to cope with the stresses of daily life.



  1. Berding, K., Bastiaanssen, T.F.S., Moloney, G.M. et al. Feed your microbes to deal with stress: a psychobiotic diet impacts microbial stability and perceived stress in a healthy adult population. Mol Psychiatry (2022).
  2. Spichak S, Bastiaanssen TFS, Berding K, Vlckova K, Clarke G, Dinan TG, Cryan JF. Mining microbes for mental health: Determining the role of microbial metabolic pathways in human brain health and disease. Neurosci Biobehav Rev. 2021 Jun;125:698-761. doi: 10.1016/j.neubiorev.2021.0044. Epub 2021 Mar 3. PMID: 33675857.
  3. Fermented foods and fibre may lower stress levels – new study, October 28, 2022, The Conversation.
  4. Fermented-food diet increases microbiome diversity, decreases inflammatory proteins, study finds. Stanford Medicine News Centre.
Ashleigh Felth…
Accredited Practising Dietitian
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    • Ashleigh Felth…