Did you know that our brain and our gut are connected?
Recent neuro-gastroenterology research has revealed extensive and direct biochemical signalling between the gastrointestinal (GI) tract and the central nervous system, referred to as the “gut–brain axis.”
This communication network is bidirectional and occurs via the autonomic nervous system, the enteric nervous system, the neuroendocrine system, and the immune system. This means the brain signals to the gut but also the gut signals to the brain!

As a result of this new understanding scientists have linked central nervous system psychiatric disorders, such as major depressive disorder (MDD), to changes in the gastrointestinal microbiome, making it a potential target for innovative antidepressant treatments. This is further corroborated by the high rate of comorbidity between psychiatric disorders and GI disorders.

It has been well established that probiotics have therapeutic effects on many GI disorders hut with the emergence of the understanding of the gut–brain axis, it has been discovered that their therapeutic effects extend beyond the gut and into the central nervous system.

There is now robust evidence of this in preclinical studies that have demonstrated probiotics’ ability to change behaviour and improve the mood, anxiety by altering neurotransmitter activity.

Diagram: The effects of depression on multiple physiological factors and their collective influence on gut health as well as mental health.

Adapted from “Flux, M. C., & Lowry, C. A. (2020). Finding intestinal fortitude: Integrating the microbiome into a holistic view of depression mechanisms, treatment, and resilience. Neurobiology of disease, 135, 104578.”.