The gut-brain connection: how our gut speaks to the brain

Trusting your gut. Can your gut influence your brain?

The discussion linking our mind and our gut has been around for a long time. We use the expression of “our gut feeling” when noticing our intuitive response to a particular situation which can guide our behaviour or reaction to it.

This gut-brain link is being investigated at the Brain-Body Institute where researchers are looking into understanding better, the relationship between our brain, nervous system and body disorders.

A new study in mice has shown how gut bacteria influence how the brain is wired for learning and memory. The bacteria we acquire in our gut just after birth appears to have a major impact on the development and function of not only the gut, but also the immune system, hormonal systems and metabolic systems. Using germ free mice they have shown how genes linked to learning and memory were altered in the hippocampus, the specialised area of the brain concerned with memory and learning.

In their studies they were able to show how gut bacteria determine how the stress response works, and this could produce an anxiety response in the brain. The findings were that the bacteria influenced the development of certain behaviours (such as anxiety) and produced neurochemical change in the brain as a result.

In other words gut bacteria can influence anxiety-like behaviours by altering the way our brain is wired.

Once we understand more about how this all the works the hope is to be able to devise more effective treatments for psychiatric disorders without having to use drugs. The current drugs available are limited in their use by the large numbers of side effects commonly experienced by people taking them.

Ref: K. M. Neufeld, N. Kang, J. Bienenstock, J. A. Foster. Reduced anxiety-like behaviour and central neurochemical change in germ-free mice. Neurogastroenterology & Motility, 2011; 23 (3): 255 DOI: 10.1111/j.1365-2982.2010.01620.x