THE GUT BRAIN AXIS

Collected, Compiled, Edited and Presented by:-

DR.V.JAGANNATHAN

 

This is fairly new topic explaining the inter relationship between the brain and the GI tract.

The gut-brain connection is complex and bidirectional. Signals pass both ways between our digestive system and central nervous system, and health or disease in one can affect the other.                                      

Key players in this connection include our enteric nervous system, our vagus nerve and our intestinal microbiome.

THE GUT BRAIN CONNECTION

Our brain talks to our gut, and our gut talks back.to the Brain. If we have ever had a “gut feeling we would have experienced this communication. It’s how the thought of an exciting event can make us feel “butterflies in our stomach,” while the thought of something dreadful might be “gut-wrenching.”and nauseating And it’s how the feeling in our gut can influence our decision-making, as in “going with your gut”.

Our brain communicates with all of our body through nerves (our nervous system). But our brain and our gut are like besties( Best Friends ) They talk about all kinds of things, from practical, physical matters to emotional ones. More information passes between our brain and our gut than any other body system. In fact, there are more nerve cells in our gut than anywhere else in your body outside of your brain. 

Function

What is the purpose of the gut-brain connection?

Our brains and digestive systems have evolved together to help us survive. What we eat is crucial to our overall health, and it has also varied a lot throughout history, depending on what was available.                    

Our brains and guts needed to stay in close contact to make sure we got the nutrients we needed. And if we ate the wrong thing, or we needed to put the brake on digestion, we had to have a good alarm system in place. 

This alarm system includes the emotional part of our brain. After a physical injury, our emotional brain kicks in to help us to remember to avoid that injury in the future. Emotion can make physical sensations in our gut seem more intense. Intense physical sensations can also raise our stress levels and our emotional response. This feedback loop is especially strong between our brain and gut.

Body functions affected by  the gut-brain connection

Studies suggest that crosstalk between our gut and brain may influence our:

• Hunger and satiety.
• Food preferences and cravings.
• Food sensitivities and intolerances.
• Gut motility (muscle movements).
• Digestion.
• Metabolism.
• Mood.
• Behavior.
• Stress levels.
• Pain sensitivity.
• Cognitive function.
• Immunity.

Anatomy

What body systems are involved in the gut-brain connection? 

What is referred as the gut-brain axis is the network of nerves that connect our brain and gut and send signals back and forth.                          

But our nervous system also works closely with our endocrine system, which produces hormones that communicate things like hunger, fullness and stress.                                                                    

And it works closely with our immune system to respond appropriately to injury or disease in our gut.

Within this network, some of the key players in the gut-brain connection include:

Enteric Nervous System

Our enteric nervous system is the neural network that operates within our gastrointestinal (GI) tract and controls its digestive functions. With more than 500 million neurons, it’s the most complex neural network outside of our brain. It’s also unique in that it can operate somewhat independently from our brain and central nervous system. This has led some scientists to refer to it as a “second brain”.

Our enteric nervous system is a special division of your autonomic nervous system, which governs the automatic functions of our internal organs.                                                                        

It operates as part of our overall autonomic nervous system, but also on its own. It can gather information about the conditions inside our GI tract, process that information locally and generate a response without sending it back to your brain.called a reflex

Vagus Nerve

Our vagus nerve is the main link between our enteric nervous system and our brain. It’s one of your 12 cranial nerves, Our vagus nerve conveys sensory information about the conditions inside our gut from our enteric nervous system to our brain. In response, it conveys motor signals from our brain to your gut.

The vagus nerve mediates various reflexes that operate within our gut in response to changing conditions, like chemical changes or the presence of food. These are called vagal reflexes. Intrinsic vagal reflexes operate within our enteric nervous system without involving our brain. Extrinsic reflexes operate through communication between our enteric nervous system and central nervous system. 

Gut Microbiome

It is interesting to note that the bacteria that live in our gut are also involved in our gut-brain connection. Gut microbes produce or help produce many of the chemical neurotransmitters that convey messages between our gut and brain. They also produce other chemicals that can affect our brain through the bloodstream. Our brain and gut, in turn, can affect our gut microbiome by altering its environment.

Recent studies have shown that the gut microbiome may be involved in various neurological, mental health and functional gastrointestinal disorders.

Functional disorders are those that cause persistent symptoms but don’t have any obvious physical or pathalogical  cause. There’s a significant overlap among people who have functional gastrointestinal disorders, like IBS (irritable bowel syndrome), and who have mental health disorders, like anxiety.

Conditions and Disorders Involving the Gut Brain Axis

Disorders related to the gut-brain axis may include:

·         Irritable bowel syndrome and functional constipation or diarrhea.

·         Anxiety and depressive disorders.

·         Noncardiac chest pain.

·         Infant colic.

·         Functional dyspepsia.

·         Functional dysphagia.

·         Gastroparesis. 

·         Anismus.

·         Chronic stress.

·         Chronic fatigue.

·         Chronic pain.

·         Visceral hypersensitivity.

·         Obesity.

·         Neurodevelopmental disorders, like autism.

·         Neurodegenerative disorders, like Parkinson’s disease.

·         Nerve-related pain disorders, like multiple sclerosis.

Care and Treatment

Healthcare providers are experimenting with treating some of these disorders by treating our gut microbiome. Animal experiments have suggested that a healthier diversity of microbiota in our gut may help to relieve gastrointestinal, neurological, inflammatory and emotional stress symptoms. Results in humans are still mixed, but intriguing.

Gut microbiome may be treated in several ways, including:

• Probiotics.
• Antibiotics.
• Fecal microbiota transplantation.

People with certain functional gastrointestinal disorders may benefit from mind-body therapy with a behavioral medicine specialist. Several different types of therapies may be beneficial in relieving persistent GI symptoms, or at least learning to cope with them. They can also help improve our overall mood and stress levels, which may help our gut indirectly. Some of these therapies include:

·         Relaxation therapy. This approach uses different techniques to help to relax and reduce the automatic reactions to stress. Techniques include progressive muscle relaxation, visualization and restful music. Research suggests these therapies are most effective when combined with cognitive behavioral therapy (CBT).

·         Cognitive behavioral therapy (CBT). The goal of this approach is to help people with GI disorders change their thoughts, behavior and emotional responses in relation to physical pain as well as mental/emotional stress and anxiety.

·         Gut-directed relaxation training. This is a combination of deep relaxation with positive suggestions focused on GI function. An example would be placing your hands on your abdomen while being asked to feel warmth and imagine having control over your GI function. This approach may be helpful for people whose symptoms occur even without obvious stress.

·         Biofeedback. This therapeutic training teaches a person how to control automatic body responses. An example would be learning how to control your heart rate or temperature with the assistance of an electronic device that provides feedback on these functions. Research has shown that biofeedback, in combination with other stress and symptom management techniques, has produced positive health effects in people with functional GI disorders.

What can we do at home to nurture our gut-brain axis?

The best way you can take care of your gut health on a day-to-day basis — and maybe your brain health, as a result — is by maintaining a healthy, balanced diet. wE can also take care of our brain health — and maybe, through it, our gut health — by doing what WE can to manage our stress.

Diet good for the gut-brain axis?

A good rule of thumb to improve our gut health naturally is to eat a good variety of whole foods, emphasizing plants. More diversity in our diet leads to a more diverse gut microbiome, which is good for our overall gut health. Whole foods and plants also pack more nutrition per calorie than processed foods, leaving less room for harmful additives, sweeteners and saturated fats. Instead,

Soluble and insoluble fiber. Most plants have both kinds of fiber, which help keep our bowels regular and feed the helpful microbiota inside. These microbes, in turn, nourish your gut lining.

• Prebiotics and probiotics. Probiotics are the live bacteria in fermented foods, like yogurt and sauerkraut. Prebiotics are the fibers and complex starches that these bacteria like to eat.
• Antioxidants. Antioxidants, which occur naturally in a variety of fruits and vegetables, help to fight free radicals in our body and prevent inflammation. Different foods have different types.
• Anti-inflammatory foods. A whole-food, plant-rich diet is naturally anti-inflammatory because it reduces sugar, additives and cholesterol. This helps keep our gut microbes happy. 

The take home message

1.Our gut and brain are in constant communication through nerves and chemical signals.                                                         

2.They’re so close that they can feel each other’s pain.                                        

3.If we have a condition that affects our digestive system or nervous system, it may also involve the other.                                            

4.Healthcare providers are beginning to approach these conditions from both sides of the gut-brain axis.                                                 

5.We can, too,do that by taking care of our mental health and gut heal

Thank you all

Collected, Compiled, Edited and Presented by:-

DR.V.JAGANNATHAN