How Your Gut Affects Your Brain & Your Mood
There have been a number of recent studies showing that the bacteria in our gut (microbiome) play a major role in determining our emotions. For example, gastroenterologists at the University of California performed brain scans on 40 healthy adults, and then looked at the different bacteria in their guts. Two of the strains of good bacteria were found to have very different effects on the way that brains grow and react to the outside world.
They found that those with higher levels of Bacteroides had thicker grey matter in the parts of the brain that help regulate moods (the frontal cortex, insula, and hippocampus regions).
Those with higher levels of the more common Prevotella showed less brain tissue in these same areas, but more connections between the emotional circuits . These people also reported higher levels of anxiety, stress, and irritability (which are all controlled by the hippocampus).
One of the main reasons for the relationship between gut bacteria and mood lies in the connection between our regular brain and our “second brain” (the enteric nervous system) in our digestive system. Our guts don’t just turn food into energy; they make up an entire ecosystem of neurons and bacteria, both of which communicate with each other and with our head brain .
Many people have experienced how strong emotions can affect your digestive system. Your enteric nervous system may cause diarrhoea, nervous ‘butterflies’ in your stomach, vomiting, etc. during times of stress. Up to 90 percent of the cells in our digestive track convey information to the brain rather than receiving signals from it, so what happens in your gut may have a greater influence on your mood than your head does.
Because gut bacteria send signals directly to the brain, they may influence how brains take shape during development, causing those with different gut bacteria to have different brain structures.
A healthy human gut is home to many hundreds of different species of bacteria, all of which are affected by what we eat, where we live, and whether we take antibiotics . So we are discovering that the phrase ‘we are what we eat’ applies to our minds and emotions as well as to our bodies.
If you have a digestive issue you would like to resolve, or if you suffer from anxiety, depression, or another emotional condition, feel free to book in for a free Comprehensive Assessment at our clinic. We can let you know what we think is causing the problem, if we think we can help you, and what treatments would be most effective. (Terms and conditions: the Assessment is a completely free service, with no obligations whatsoever.)
 Tillisch, Kirsten, et al. Brain structure and response to emotional stimuli as related to gut microbial profiles in healthy women. Psychosomatic Medicine. June 2017. doi: 10.1097/PSY.0000000000000493