Gut feelings- the link between the Microbiome and Mental Health by Juleyka Uddin

Written by Juleyka Uddin

We’ve all heard about the gut-brain connection, but what does that really mean? Research has been conducted over the past few years to uncover the link between our gut microbiome and mental health. This post is the start of a miniseries which will explore how our gut microbiome affects mental health with a focus on; ADHD, depression, anxiety, and symptoms related to these conditions.

The Gut-Brain Connection Explained

Our gut microbiome is a collection of bacteria, fungi, viruses, and other microorganisms that live in our guts. Together, these microorganisms make up an ecosystem with a powerful influence on our physical and mental health. This system is known as the gut-brain axis, or “brain-gut connection” — it’s the communication between your digestive system and your brain.

The role of probiotics and prebiotics in mental health

Research has shown that probiotics can help to improve gut health and impact mental health by influencing the levels of neurotransmitters such as serotonin and by reducing inflammation in the gut. This can have a positive effect on mood, anxiety, and depression. Probiotics have an important role to play as they enhance immunity, protect the intestinal lining from any pro-inflammatory molecules, which in turn prevents any pro inflammatory compounds from entering the gut and the brain (via the blood brain barrier).Due to this anti inflammatory effect, probiotics have been shown to have anti-depressive properties as they promote the production of tryptophan, which is a precursor to serotonin. Adequate levels of this neurotransmitter have been linked with good mood and feelings of wellbeing.

Prebiotics on the other hand are also another essential component of the microbiome, they are classed as ‘food’ for probiotics. They come in the form of either soluble or insoluble fibre, swell as fermentable fibre which is an essential for supporting the growth of good bacteria in the gut.

It is recommended to consume a variety of fibre-rich foods such as fruits, vegetables, whole grains, legumes, and nuts to get a good mix of prebiotics and fibre. Fibre can be supplemented in the form of psyllium husk powder/capsule’s/flax seed sprinkled over foods or also in supplement form.

It is important to note that while supplements can be a convenient way to get pre- and probiotics, it is always best to get these nutrients from whole food sources. Whole foods work in synergy with other nutrients in food, providing more benefits to overall health than just taking supplements alone.

However, for those who have difficulty getting enough fibre and prebiotics from their diet, supplements can be a good option. It’s always best to consult with a healthcare professional before starting any new supplement regimen, especially for individuals with any medical conditions or taking any medications.

Bottom line

There is growing evidence to support a strong link between our gut microbiome and mental health outcomes such as ADHD or depression. By understanding this link better, we can develop more effective treatments for these conditions including dietary interventions aimed at balancing our microbiome. Nutrition graduates should take note of this research as it could provide valuable insights into new approaches for treating mental health disorders in the future.

Stay tuned for part 2 of the miniseries were Juleyka will delve deeper into the research behind probiotics and mental health!


  1. Clapp, M., Aurora, N., Herrera, L., Bhatia, M., Wilen, E. and Wakefield, S. (2017). Gut microbiota’s effect on mental health: the gut-brain axis. Clinics and Practice, [online] 7(4). doi:
  2. Appleton, J. (2018). The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health. Integrative Medicine: A Clinician’s Journal, [online] 17(4), pp.28–32. Available at:
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