Gut-Brain Axis: What is it, and why is it important?

We’ve all had a “gut feeling” that’s led us to make one decision over another, right? The idea that the gut microbiome impacts our behavior and neural development is a well-received topic among interdisciplinary researchers in endocrinology, nutrition, neurology, biochemistry, microbiology, and immunology. At the same time, beginning to understand the mechanisms at play is a relatively new hot topic that’s influencing scientific exploration, especially in human clinical studies.

Overall, there’s overwhelming evidence suggesting that the trillions of bacteria in the gut play a key role in how the gut and brain communicate with each other. It’s like a two-way street, which is how the term “gut-brain axis” originated. This concept has been studied to explain regulation of our mood, personality, and even severity of mental illness. But just how does this even happen?

3 Keys To Gut-Brain Axis

There are millions of nerves connecting the brain to the gut, and the main three pathways being researched to explain this are the vagus nerve, immune, and neuroendocrine systems. The vagus nerve is the primary nerve that stretches from the brain to the abdomen, carrying the responsibility of regulating heart rate, digestion, and breathing rate. It comprises efferent (motor) and afferent (sensory) neurons that work together to carry signals between the brain and organs, including the intestines, which are influenced by gut bacteria. Through these signals, the brain can gather what the microbial environment looks like in the gut and respond accordingly.

Similarly, the immune system has a critical role in brain health through its heavy influence on the GI tract. Ever been told that antibiotics “kill all the bacteria, even the good kind?” Well, they’ve indeed been well-studied to do so, and possibly even trigger conditions like inflammatory bowel disease (IBD) in the process. Further, growing research has suggested that neurological conditions like Alzheimer’s disease have low-grade inflammation that’s suggestive of an impaired immune system and an imbalance in the microbiome.

Encompassing both of the main roles of the immune system and the vagus nerve, the neuroendocrine system regulates our hormones and overall well-being. The bidirectional communication processes between this system and gut microbiome are linked with emotional dysregulation and mood disorders like anxiety and depression when there are disturbances. This has been seen in people with IBD or IBS, as they’ve been shown to have a greater likelihood of suffering from mental health conditions.

The gut-brain relationship is rightfully gaining more traction among all sorts of people within and outside of science and research, especially because it could possibly answer a lot of burning health questions.

Here’s a look at articles published on GutNews that demonstrate the gut-brain axis:

MORE: Gut-Brain Connection articles on

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