Gut Health: The Surprising Connection Between Digestive System and Brain

… In recent years, there has been a surge in research interest in the interactions between the digestive system and brain functions. These bidirectional interactions occur in the gut-brain axis, or the microbiota-gut-brain axis. The intestinal barrier, with its surface area, plays a crucial role in the interaction between the internal and external environment of the human organism’s vitality. As the largest immune organ in the human body, the functions of the intestinal barrier are critical in immunomodulation and antibody production. These functions are substantially influenced by food consumption and exposure to food antigens. Moreover, psychological stress can substantially influence the physiology and permeability of the intestinal barrier. The coexistence of psychiatric illnesses with multiple gastrointestinal disorders, such as inflammatory bowel disorders (IBD) and irritable bowel syndrome (IBS), indicates the significance of the gut-brain axis in the context of mental health.

The Connection Between Serotonin and Gut Health

An estimated 90% of the body’s serotonin is produced in the gut, where it influences gut immunity. The discovery has shown that selective serotonin reuptake inhibitors (SSRIs) are not as effective in treating conditions such as depression as once believed. If you are taking SSRIs, work with your GP to taper down the dosages if possible and try alternative things like improving your gut health with more whole grains, nuts, veggies, beans, fresh fruits, pickles, and sauerkraut.

Fecal Microbiota Transplantation

The Chinese have understood the importance of gut health since the 4th century. They administered a fecal slurry known as yellow poop soup. As disgusting as it sounds, the use of fecal microbiota transplantation has shown to be effective in many situations when tested on animals.

Cutting Out Gluten and Dairy

Cutting out gluten and dairy can potentially help someone eliminate two major sources of inflammation. “In those with celiac disease or any demyelination illness, casein can cross-react with gluten, meaning the body mistakes the casein for gluten, causing inflammation and furthering issues of leaky gut. This would also likely improve overall gut health."

The Gut Brain axis

The gut-brain axis refers to the bidirectional communication between the central nervous system (CNS) and the enteric nervous system (ENS), which is responsible for the control of gastrointestinal function. The concept of the gut-brain axis is not a new one, and historical reflections on this topic reveal that it has been studied for centuries.

As early as the fourth century BC, Hippocrates recognized the connection between the gut and the brain, and he believed that food affected a person’s mental state. However, it wasn’t until the early 20th century that scientists began to systematically study the gut-brain axis. In the 1920s and 1930s, researchers such as Walter Cannon and Hans Selye demonstrated that stress could lead to changes in gastrointestinal function, and that the gut and the brain were connected via the sympathetic nervous system.

In the mid-20th century, the concept of holism in biomedicine emerged, which emphasized the interconnectedness of various body systems. This approach led to an increased interest in the gut-brain axis, and researchers began to study the role of the ENS in gastrointestinal function and its communication with the CNS.

In the 1980s, the discovery of neuropeptides in the gut, such as substance P and vasoactive intestinal peptide, further supported the idea of the gut-brain axis. More recent advances in technology have allowed researchers to study the gut microbiome and its role in the gut-brain axis, and this area of research is currently a major focus of study.

Overall, historical reflections on the gut-brain axis demonstrate that this concept has been recognized for centuries, and that scientific study of this connection has led to important advances in understanding the role of the gut in overall health and well-being.


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The gut-brain axis plays a critical role in the interaction between the internal and external environment of the human organism’s vitality. The gut is the largest immune organ in the human body, and its functions are critical in immunomodulation and antibody production. The connection between serotonin and gut health is significant, and SSRIs are not as effective in treating conditions such as depression as once believed. Fecal microbiota transplantation and cutting out gluten and dairy are alternative approaches to improving gut health.S