Scientists continue to deepen our understanding of the bi-directional exchange between the gut and the brain, with most research investigating the communication from the GI tract to the central nervous system. The focus is usually on what to eat to feed the beneficial bacteria in our gut that facilitate cognition, and which probiotics could improve our mental health. But if what’s going on in our gut can change our mental health, thoughts, memory, and cognition, could what’s going on in our brain likewise alter our gut function? And more specifically, could our thoughts and stress levels actually change the composition of our gut microbiome and therefore impact our disease risk and aging process? While there’s less research on brain-to-gut communication, recent studies show that the communication from our brain to our gut may be just as immediate and impactful as the gut-to-brain pathways.
In 2024, a compelling article published in Cell found that psychological stress can alter the gut microbiome within hours, and in turn negatively affect the immune system. This study looked at the vagus nerve, which connects the amygdala in the brain to glands in the small intestine through a neural circuit. Scientists discovered that stress diminishes amygdala activity, which lowers vagus nerve activity, and results in less mucus production from the glands. A decrease in mucus was associated with impaired growth of beneficial gut bacteria like Lactobacilli, and increased risk of infection. A 2025 article published in New Scientist uncovered similar findings and found that brain signals in mice can alter gut bacterial composition in as little as 2 hours!
We’ve long hypothesized that stress and negative thinking can lead to lower immunity, increased infection, and even heightened disease risk. These articles tell us more about how the gut facilitates the relationship between stress and infection/disease and illustrates the impact of our brain activity on our overall health. Bottom line: positive thinking and stress management are integral to optimal gut health. Looking for ways to manage stress? Click here!
