Dylan Stoll | Health Editor
Featured Image: The stomach has been found to have a multitude of links to the brain’s activities. | Pixabay
When searching for answers to the more pressing questions surrounding mental health, the last place one would assume to look would be the stomach; however, one would be wrong. In February 2019, researchers published a paper in Nature Microbiology where they described their discovery of a link between the prevalence of specific types of bacteria in the gut and depression in the host. What they found was that the examined patients suffering from depression also had a lower amount of the Coprococcus and Dialister bacteria within their gut microbial community, otherwise known as the gut microbiome.
“If you would have asked a neuroscientist 10 years ago whether they thought the gut microbiota could be linked to depression, many of them would have said you were crazy,” said Jeroen Raes, a systems biologist and microbiologist from Belgium, interviewed by TheScientist.
Interestingly, a different team of researchers published a separate paper later that month. They describe a correlation between higher amounts of a few different types of bacteria within the gut microbiome, including Veillonellaceae and Lachnospiraceae, and another mental ailment known as schizophrenia. They found that they could effectively determine whether a patient had schizophrenia or not through an analysis of their gut microbial content.
Dr. Myriam Mongrain, a professor of psychology at York, touches on the subject from a psychological perspective. “People often get depressed after experiencing loss or failure, and make no changes to their diet and yet get depressed. So we also have to consider psychological factors for the illness,” explains Mongrain.
“I have seen a lot of research on Irritable Bowel Syndrome, stress, and the gut microbiome. Mood disorders have also been implicated, but we should not lose sight of other influences in the production of serotonin (like perceived stress) that will contribute to symptoms.”
Be that as it may, there are other studies that connect the mind with the stomach, although unrelated to microbial content.
“This kind of literature does exist. There is a connection between the gut and neurochemical secretions that later affect the brain. However, it’s important to consider the full picture,” says Mongrain.
This connection, or one of many possible connections, is called the vagus nerve, travelling from the gut to the brainstem. In 2010, a neuroscientist by the name of Diego Bohórquez discovered that a type of cell that lines the inner wall of the gut, otherwise known as enteroendocrine cells, had foot-like protrusions that are similar in appearance to the synapses of neurons. This similarity drove him and his colleagues to determine what these synaptic-like structures may be partnered to. Through the use of a fluorescent marker capable of being transmitted through neuronal synapses, they were able to find that the partner of the enteroendocrine cells were in fact the vagal neurons that make up the aforementioned vagus nerve; the physical connection between the stomach and the brain.
And yet another study published in September 2018 focused on the gut-brain link, specifically the sensory cells of the stomach. Using a laser, the researchers stimulated the gut sensory cells of mice. The end result was dopamine: a neurotransmitter that plays an integral role in the reward system of the brain.
So it stands to show that the mind and the stomach are inexplicably connected. This could mean that our daily choices in food and beverage may also affect our mood, whether it be in the moment or in the future. With that sudden uptake of dopamine, you may enjoy that soft drink today, but will the increase in acidity thereafter disrupt your microbiome, changing your mood for the worse tomorrow? Food for thought.
