Within the walls of the digestive organs lies a hidden brain. We examined how this alters the perception of the link among digestion, disposition, wellness, and even thought.
The Enteric Nervous System — The Brain in the Belly
This is a component of the autonomic nervous system situated in the intestinal walls. The enteric nervous system contains as many neurons as the spinal cord. Its primary function is to manage digestion. It controls processes starting from swallowing and the secretion of digestive enzymes, extending to the distribution of blood flow which aids the body in absorbing useful substances and shedding what is unnecessary. Although the enteric nervous system lacks cognition in the usual sense, it is closely linked to the brain—it is this interplay that can surprisingly impact well-being, mood, and overall health.
Hormones of Delight and Strain
The gut microbiota influences the production of several hormone groups and neurotransmitters involved in regulating disposition and the response to stress—from serotonin to hormones related to appetite.
Approximately 90–95% of all serotonin in the body is synthesized right in the gut by specialized mucosal cells and symbiotic microbes. However, this “gut” serotonin does not travel to the brain directly, as it cannot cross the blood-brain barrier—a protective filter between the circulatory system and the brain. Instead, it acts indirectly—by stimulating the vagus nerve, sending signals to the cerebrum, and regulating processes that affect cognitive functions and emotional state.
The byproducts of bacterial life take part in regulating hormones like glucagon-like peptide-1 (GLP-1), which helps manage feelings of satiety and indirectly affects mood and drive.
Furthermore, the microbiota can participate in regulating stress hormones by influencing the hypothalamus-pituitary-adrenal axis. Animal studies reveal that a lack of microbiota leads to an imbalance in this axis and an increased release of stress hormones at specific times of the day. Restoring the microbiota, conversely, helps reestablish rhythm and an appropriate reaction to strain.
How the Microbiota Contributes to Decision Making
Recent inquiries confirm that the gut can be regarded as a “second brain.” Scientists are increasingly obtaining practical evidence that intestinal microbes can affect brain function and behavior through the so-called gut-brain connection.
Signals from the gut via the vagus nerve help regulate crucial functions such as anxiety, mood, learning, memory, and motivation. This suggests that the gut is involved in processes that determine how an individual reacts to the surrounding world.
Moreover, evidence exists that the link between the gut and the brain also impacts social conduct. For example, in young individuals with alcohol overuse, the operation of this system is linked to peculiarities in emotion perception and impulsivity levels. Scientists have also found a connection between certain gut bacteria and emotional reactions.
How This Changes the Approach to Health
Scientists are increasingly exploring the relationship between gut bacteria and brain function, and the findings from these studies appear very promising. They help to better grasp how various physical ailments and mental disorders develop, as well as how viruses and bacterial infections might affect the brain.
One instance is the long-term effects of COVID-19, where changes in the gut microbiome might be associated with the emergence of neurological symptoms post-illness. Understanding how gut bacteria influence the brain may, in the future, help physicians detect depression, anxiety disorders, and neurodegenerative diseases earlier, as well as select more precise and effective treatments.
For the “second brain” to make sound choices, it requires support:
Fiber Diversity. The more varied the fruits and vegetables, the more stable the microbiota.
Fermented Foods. Yogurt, kefir, sauerkraut—direct nourishment for beneficial bacteria.
Sugar Reduction. Excess sugar feeds pathogenic bacteria that promote inflammation and impede clear thinking.
The Main Point: A “Second Brain” is Concealed in the Gut
The enteric nervous system manages digestion and is closely tied to the brain. It impacts disposition, strain, and cognitive functions.
The gut microbiota assists in producing serotonin and other hormones, controls appetite, emotional condition, and stress response. Although gut serotonin does not reach the brain directly, via the vagus nerve and immune signals, it indirectly influences behavior, motivation, and emotion perception.
Supporting the microbiota through fiber, fermented items, and sugar reduction helps the “second brain” function correctly; this can boost well-being and brain health.
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