Can Healthy Gut Contribute To Healthy Brain?

Gut and Brain

The gut-brain connection is a complex network of interactions between the central nervous system (CNS) and the enteric nervous system (ENS). This connection allows bidirectional communication between the gut and the brain through the nervous system, immune system and endocrine system. One of the main pathways involved in the gut-brain axis is the vagus nerve, which connects the ENS to the CNS. The vagus nerve is the largest nerve of the parasympathetic nervous system, which is responsible for rest and digest functions. The vagus nerve sends signals from the gut to the brain, and from the brain to the gut, which can affect gut motility, gut secretion, and gut immune function. The vagus nerve also plays a role in regulating the release of neurotransmitters, such as acetylcholine and norepinephrine, which can affect brain function.

Research has shown that a healthy gut microbiome is crucial for maintaining optimal mental health and that imbalances in gut bacteria can contribute to the development of mental health disorders such as anxiety and depression. The gut-brain axis has been implicated in a wide range of neurological and psychiatric disorders, including Parkinson’s disease, Alzheimer’s disease, depression, and anxiety. Dysfunction of the gut-brain axis has been suggested to contribute to the pathogenesis of these disorders.

Studies have also shown that people with mental health disorders such as depression and anxiety tend to have different gut microbiota profiles compared to healthy individuals. For example, one study found that people with depression had reduced levels of certain bacteria in their gut, including Faecalibacterium and Coprococcus, which are known to produce anti-inflammatory compounds.

Some Functions of Gut Microbiota/Bacteria:

1. Produce short-chain fatty acids (SCFAs), which are important for maintaining the integrity of the gut lining and regulating immune function. Studies have found that individuals with mood disorders such as depression have lower levels of SCFAs, indicating an imbalance in gut bacteria.
2. Produce neurotransmitters such as cortisol (stress hormone), serotonin, dopamine, and gamma-aminobutyric acid (GABA), which are essential for regulating mood, anxiety, and stress. Stress, especially chronic stress, can lead to an imbalance in gut bacteria, which can, in turn, lead to the development of mental health disorders. When the body is under stress, the sympathetic nervous system is activated, which can lead to changes in gut motility, permeability, and the composition of the gut microbiota.
3. Regulates the immune system. An imbalance in gut bacteria, such as from antibiotic use, a high-fat diet, or stress, can lead to changes in neurotransmitter production and activity, as well as inflammation in the gut and brain. Inflammation is a normal response of the immune system to injury or infection, but chronic inflammation has been linked to a range of mental health disorders, including depression, anxiety, and schizophrenia.
4. Supports gut’s permeability. Gut permeability refers to the degree to which the gut allows substances to pass through its walls into the bloodstream. When the gut is healthy, it only allows necessary nutrients to pass through, but when it is damaged, it can allow harmful substances such as bacteria and toxins to enter (Gut leak) the bloodstream, leading to inflammation and potential harm to the brain (neurodegeneration).

Link to Parkinson’s Disease

In recent years, there has been growing interest in the link between the gut microbiome and neurological disorders such as Parkinson’s disease. One study found that people with Parkinson’s disease have a different gut microbiome composition than healthy individuals. Specifically, they had lower levels of bacteria that produce short-chain fatty acids (SCFAs). Another study found that a particular strain of bacteria, called Akkermansia muciniphila, was significantly reduced in people with Parkinson’s disease compared to healthy individuals. This strain of bacteria has been shown to have anti-inflammatory properties and to improve gut barrier function. In addition, studies have found that individuals with Parkinson’s disease have increased intestinal permeability.

Research has also shown that the gut microbiome may be involved in the development and progression of Parkinson’s disease. In animal studies, researchers have found that disrupting the gut microbiome can lead to an increase in alpha-synuclein protein, which is a hallmark of Parkinson’s disease. This suggests that the gut microbiome may play a role in the aggregation of alpha-synuclein and the formation of Lewy bodies, which are a key feature of Parkinson’s disease.

A recent review of studies on the gut microbiome in Parkinson’s disease concluded that there is evidence to support the role of gut dysbiosis (disruption to Microbiome) in the pathogenesis of Parkinson’s disease. The review also found that certain dietary interventions and probiotics can modulate the gut microbiome and improve symptoms in individuals with Parkinson’s disease.

Ways to Improve Health thru Gut

It is clear by now that maintaining a healthy gut microbiome is important for everyone, especially for people with Parkinson’s disease. Here are several ways to protect and improve gut health:

Eat a healthy, balanced diet

(See also Natural Ways To Avoid Constipation)

A diet that is high in fiber, fruits, vegetables, lean protein sources, and whole grains can help promote the growth of beneficial gut bacteria and improve gut health. A dietary intervention that has shown promise is the Mediterranean diet, which is rich in fruits, vegetables, whole grains, and healthy fats. A study found that adherence to the Mediterranean diet was associated with a reduced risk of Parkinson’s disease.

1. Fiber: Soluble and insoluble fibers provide bulk to the stool, promote regular bowel movements, and serve as a prebiotic to feed beneficial gut bacteria. The recommended daily intake of fiber varies depending on age, gender, and physical activity level. Generally, the recommended daily intake of fiber is:

• For adult women: 25 grams per day
• For adult men: 38 grams per day

However, some experts suggest that people should aim for even higher amounts of fiber, such as 30-40 grams per day, to further promote gut health and reduce the risk of chronic diseases. While fiber is important for gut health, consuming too much fiber can have side effects on the gut.

• Bloating and gas: Consuming too much fiber can cause bloating and gas, especially if you increase your fiber intake too quickly.
• Constipation or diarrhea: Consuming too much fiber can cause constipation or diarrhea, depending on the type of fiber and how much water you drink.
• Nutrient deficiencies: Consuming too much fiber can interfere with the absorption of certain nutrients, such as iron, calcium, and zinc.
• Intestinal discomfort: Consuming too much fiber can cause intestinal discomfort, such as cramping and abdominal pain.

It is important to note that the amount of fiber that is considered “too much” can vary from person to person and depends on factors such as age, gender, and physical activity level.

2. Probiotic: Probiotics are live microorganisms that provide health benefits to the host by restoring and maintaining the balance of gut bacteria. Look for a probiotic supplement that contains a variety of strains of bacteria. One study found that probiotics can improve symptoms of depression and anxiety in people with irritable bowel syndrome (IBS). Probiotics, when consumed, have also been studied for their potential therapeutic benefits in Parkinson’s disease. On another study the use of a specific strain of probiotic led to improvements in motor function and reduced inflammation in individuals with Parkinson’s disease.
3. Prebiotics: Non-digestible fibers that serve as food for beneficial gut bacteria. A study found that the use of prebiotics led to improvements in motor function and reduced inflammation in individuals with Parkinson’s disease.
4. Fermented foods: Fermented foods, such as yogurt, kefir, and kimchi, are rich in beneficial bacteria that can help improve gut health.
5. Polyphenols: Plant compounds that have anti-inflammatory and antioxidant properties, which can reduce inflammation in the gut.
6. Omega-3 fatty acids: Essential fatty acids that have anti-inflammatory properties and can help reduce inflammation in the gut. Another study found that a dietary intervention that included probiotics, prebiotics, and omega-3 fatty acids improved depression and anxiety symptoms in people with major depressive disorder.
7. Vitamin D: A nutrient that is important for gut health, as it regulates the immune system and can reduce inflammation in the gut.
8. Zinc: An essential mineral that is important for maintaining a healthy gut lining and preventing leaky gut.

Stay hydrated

Drinking enough water can help promote regular bowel movements and prevent constipation, which is pretty common with PD patients.

Manage stress

Stress, especially chronic stress, can disrupt the gut microbiome and lead to inflammation. Engage in stress-reducing activities such as meditation, yoga, or deep breathing exercises.

Get enough sleep

Lack of sleep can disrupt the balance of gut bacteria and lead to inflammation in the gut.

Avoid antibiotics unless necessary

Antibiotics can disrupt the balance of gut bacteria, so it is important to avoid them unless they are necessary. Talk to your doctor about alternatives if possible.

In summary, the gut-brain connection is a complex and bidirectional relationship through the gut-brain axis, with disruptions in gut health potentially leading to changes in neurotransmitter production, inflammation, and harmful substances entering the bloodstream. Improving gut health through dietary changes, exercise, probiotics, and other various interventions may have positive effects on overall health, especially for Parkinson’s disease patients.