Author: Josna Lewis
what is Connection between Brain and Gut ?
We all have experienced the “gut feeling” or “butterflies in the stomach” during pleasure or when you are nervous or “stomach wrench” when you are stressed or something absurd happens and imbalances your digestive function, and ever wondered how?
Here is something to know!
There is the gut-brain axis and is bidirectional central nervous system (CNS) communicates with the enteric nervous system (ENS). The axis is not just an anatomy but extends to endocrine, humoral, metabolic, and immune routes of communication as well. The autonomic nervous system, the hypothalamic-pituitary axis-adrenal (HPA) axis, and the enteric nervous system link the brain and gut. Studies state that enteric microbiota influences the brain-gut relationship (intestinal regulation, mental/ emotional regulation, neuromuscular regulation).
Brain-Gut Axis
The bidirectional communication pathway includes the central nervous system (CNS) (brain and spinal cord), the autonomic nervous system (ANS), the enteric nervous system (ENS), and the hypothalamic-pituitary-adrenal (HPA) axis, allowing the brain to influence all gut activities, also influence mood, cognition and mental stability.
Neurological Pathway
- Autonomic Nervous System
The ANS (sympathetic and parasympathetic) drives the afferent signals from the lumen of the intestine through the enteric, spinal, and vagal pathway and efferent signals from the CNS to the intestinal wall. The ANS (sympathetic and parasympathetic) drives the afferent signals from the lumen of the intestine via the vagus nerve and is responsible for motility, peristalsis, and acid secretion, and affects mood and behavior.
- Enteric Nervous System (ENS)
The ENS (Second Brain) can function independently of the central nervous system (CNS), which contains afferent neurons, interneurons, gut neurons, it regulates all the aspects of digestion without input from the brain. However, ENS communicates via the vagus nerve and sends signals in both the direction and efferent signals from the CNS to the intestinal wall.
Though ENS can function without CNS, it does not normally do so, CNS affects the enteric behavior as the gut sends signals to the brain. 90% of the vagal fibres are afferent and hence brain is more of a receiver than a transmitter in brain-gut communication.
Neuroendocrine/ Metabolic Pathway
- Hypothalamic-pituitary-adrenal (HPA) axis
Stress activates the HPA-axis, it is the core stress efferent axis, and coordinates adaptive responses to stressors of any kind and releases cortisol from adrenal glands and impacts a stress hormone that can impact immune cell activity and affect the gut motility, and permeability and affect the gut microbiota. This communication is mediated by microbially derived molecules short-chain fatty acids, bile acids, and tryptophan metabolites (required for brain development). Abnormality in the HPA axis during brain development may affect microbial colonization.
- Enterochromaffin Cell Signalling
50% of dopamine and 95% Serotonin are stored in enterochromaffin cells of the gut. Serotonin regulates GI motility, secretion, sleep, appetite mood. The gut microbiome regulates the serotonin and other neurotransmitters such as dopamine, GABA, norepinephrine, and glutamate synthesized through various proteins. Dysfunction in these neurotransmitters and the gut microbiome impairs brain function, sleep, mood, and mental health.
Hence, we can relate why anxiety, depression messes with stomach or indigestion can make us irritable or anxious.
Functions of Gut-brain axis
The Gut-brain axis may influence
- Hunger and satiety
- Food intolerance
- Digestion
- Gut motility
- Metabolism
- Mood
- Behaviour
- Stress level
- Cognitive functions
- Pain stimulus
- Immunity
Conditions and Disorder
- Digestive disorders
- Irritable bowel syndrome
- Dyspepsia
- Gastrointestinal problems
- Chronic stress related problems
- Obesity
- Autism
- Parkinson’s Disease
How To Maintain Gut-Brain Connection
To maintain your gut health/ gut microbiome it is important to have a strong balance of intestinal flora in the gut. A healthier gut microbiome in your gut helps to relieve gastrointestinal, neurological, inflammatory, and emotional stress symptoms.
- Diet
Taking well balanced, nutritional diet. Consuming a diverse range of whole foods, including fruits, vegetables, whole grains, lean proteins, and healthy fats, provides essential nutrients and fiber that support gut health. Fiber-rich foods, in particular, promote the growth of beneficial gut bacteria and contribute to a healthy microbiome, which is crucial for gut-brain communication. Probiotic-rich foods such as yogurt, kefir, sauerkraut, kimchi, and prebiotic foods like garlic, onions, bananas, and asparagus serve as fuel for probiotics and help nourish the gut microbiota.
For example: In a few cases, irritable bowel syndrome (IBS) is a common gut disorder that might be anxiety-related as well, so instead of directly going in for medication regulating intestinal absorption through prebiotic or probiotics and balanced nutrition can help patients with no pervious illness.
- Stay Hydrated
Drinking adequate water throughout the day supports digestion, nutrient absorption, and overall gastrointestinal function.
- Manage Stress
Stress may disrupt the gut-brain axis and cause gut problems. Prebiotic foods like garlic, onions, bananas, and asparagus serve as probiotics and help nourish the gut microbiota. Cognitive therapies or relaxation therapies to calm down the mind.
- Regular Physical Activity
Exercise always has positive effects on gut health and microbiota composition and in turn overall health. Regular physical activity can improve gastrointestinal motility, improve digestion, reduce inflammation, and enhance mood, all to a healthy gut-brain axis.
- Get Adequate Sleep
Quality sleep is essential for maintaining optimal brain function and supporting gut health. Aim for restful night sleep, as inadequate sleep can disrupt circadian rhythms, impair cognitive function, and alter gut microbiota composition.
- Seek Professional Guidance
If you experience persistent gastrointestinal symptoms or mental health concerns, consult with a healthcare provider or registered dietitian. They can provide personalized recommendations and interventions to address specific issues and support a healthy gut-brain connection.
Conclusion
The intricate connection between the brain and the gut, known as the gut-brain axis, plays a crucial role in regulating various aspects of our physical and mental health. This bidirectional communication pathway involves the central nervous system, autonomic nervous system, enteric nervous system, and neuroendocrine pathways, allowing for the exchange of signals that influence digestion, mood, cognition, and overall well-being.
By nurturing our gut microbiome and addressing lifestyle factors, we can enhance our physical, mental, and emotional well-being, underscoring the profound interconnectedness of our bodies and minds.
We always experience “gut feelings” or “gut wrenches” and it is intriguing to know the physiology behind it. So next time you experience these feelings know that your brain is communicating with your gut and sending you signals.
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