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Could your headaches be coming from your gut? (Part 1)

Man with headache pain

Many people suffer from headaches these days and there are many reasons why this is happening.

Causes of headaches

Minor headaches can be caused by a cold or flu, dehydration, stress, or eyestrain. More serious headaches and migraines have been linked to other causes, ranging from simple to very serious.  More studies are pointing towards the link between gut health and headaches.

We are made of individual organs but none of these functions individually: they are all interconnected through a complex and wonderful network within our body. This indicates that when we are experiencing a problem in one place, we should not dismiss the possibility of it coming from an entirely different place.

What is the role of the gut-brain axis on headaches?

One major connection within our body is what is known as the gut-brain axis: it is the link between our gut and our brain. It is a bidirectional system that allows communication between our gut and our brain via the vagus nerve. There is a constant communication between these two systems and this is done through neurotransmitters such as serotonin, dopamine, CGRP (calcitonin gene-related peptide, the gene targeted by migraine drugs such as anti-CGRP medications), GABA (gamma-aminobutyric acid), etc… These have antimicrobial properties on many gut bacteria and are essential for brain function. It is important to note that serotonin, which is a key neurotransmitter in relation to headaches and migraines, is mostly produced in the gut thus poor gut function lead to poor production of this important neurotransmitter.

Any disruptions in these communications between our gut and our brain can lead to dysfunction, and cause as many issues as headaches, fatigue, low energy, poor mood, anxiety, depression, bloating, weight gain, pain, skin issues, infections, allergies, poor memory and concentration, stress and sleep problems. This explain why so many patients suffering from these symptoms are often also found to be suffering with digestive issues for many years before their symptoms appeared.

How does it work?

The mechanisms explaining how the gut and the brain interact in such conditions are not entirely clear but studies suggestfactors such as inflammatory mediators (i.e. substances causing inflammation);

gut microbiota status – gut infections; neurotransmitters pathway; stress hormones; or nutritional imbalances.

A number of studies point to what is known as ‘leaky gut’ or intestinal permeability. As discussed in previous blogs, ‘leaky gut’ allows large molecules (such as bacteria, undigested foods, toxins…) to go through the tight junctions of our gastro-intestinal tract. These then reach our bloodstream and trigger an immune reaction causing inflammation. As the gut and the brain are connected, this means that an inflamed gut leads to an inflamed brain: neurons become inflamed and lead to pain, there are changes in blood vessels and blood flow to the brain as well, setting in motion the symptoms mentioned above.

The gut microbiota

Our gut houses 100 trillion of bacteria, part of the so-called “microbiota”: our gut bacteria are influenced by what we eat, our environment and our lifestyles. Healthy gut bacteria allow the production of the neurotransmitters we discussed before. It is therefore essential to take care of our gut bacteria and variety is the key. If our gut does not house a good variety of bacteria, it can cause imbalances that lead to distress: this happen when there are too many pathogenic bacteria (causing diseases) and not enough ‘good’ ones. This puts the gut under stress, and triggers headaches, migraines…

Thus a healthy digestive system will produce adequate quantities of neurotransmitters; this keeps digestive pain away, and thus headache and/or migraine pain away.

In Part 2, we will be looking at ways to support you naturally in order to reduce these symptoms.

If you are suffering from headaches or any of the symptoms mentioned in this blog, we recommend you consult with a Gut Health Nutritional Therapist. You can get in touch with me here or call me on 07788 444 199.


Arzani, M.  Jahromi, S.R. Ghorbani, Z. et al. (2020) ‘Gut-brain Axis and migraine headache: a comprehensive review’, The Journal of Headaches and Pain, 21 (15).

Chen, J. Wang, Q. Wang, A. et al. (2019) ‘Structural and Functional Characterization of the Gut Microbiota in Elderly Women With Migraine’, Frontiers in Cellular & Infection Microbiology.

Gershon, M. D. (1998). ‘The Second Brain: A Groundbreaking New Understanding of Nervous Disorders of the Stomach and Intestine’, New York, HarperCollins Publishing.

Gokani, T. (2017) ‘The Gut-Brain Link: How your headaches might stem from your digestion’, HuffPost.