The Smart Gut: Links between Intestinal Microbes and ADHD

By Dr Chia Boon Tat

THE SECRET TO BRAIN HEALTH LIES IN OUR GUT

Embedded in the wall of our gut, lies a complex nervous system comprising an estimated 500 million neurons. Sometimes called the “Second Brain”, this enteric nervous system (ENS) can work independently of and in conjunction with the brain in our heads. Although it is not capable of cognitive thoughts, it is capable of “thinking”, “remembering” and “learning”, and accounts for our emotional and mental health.

Information flows back and forth continuously between the brain and our gut via an information expressway, called the gut-brain axis. An example of the gut-brain connection at work is the sinking feeling we get in the pit of our stomach during a stressful event. So is the “gut feeling” when meeting somebody for the first time or relying on “gut instinct” when faced with making a difficult decision.

The brain can control environmental conditions in the gut such as the rate at which food is being moved and the amount of mucus lining the gut. This has a major impact on our gut microbiome – the 100 trillion bacteria of several thousand species living in the gut. These microbes perform beneficial functions such as food digestion and making vitamins. They play a fundamental role in our immune system and constitute the first line of defence against pathogens. The gut microbiome can modify very rapidly when adjusting to change in diet or a stress-induced decrease in gut transit time. Through the gut-brain axis, the gut microbes inform the brain of the changes and eventually influence our mind: shaping our perception of the world and altering our behaviour[ii].

The communication between the brain and gut uses more than 30 neurotransmitters (brain chemicals), most of which are biochemically-identical to those found in the brain. The gut microbiome directly influences the levels of these neurotransmitters. For example, it is estimated that our gut produces 50 per cent of dopamine and over 90 per cent of the serotonin in the body[iii]. These neurotransmitters regulate our mood, and recent studies have linked their deficiency to the onset of neurological disorders including anxiety, depression, ADHD, ADD and autism spectrum disorder. Although these neurotransmitters do not enter the brain (the brain synthesizes its own neurotransmitters), they do provide an indication of our emotional and mental health. 

DYSBIOSIS, INTESTINAL PERMEABILITY AND NEURODEVELOPMENTAL DISORDERS

In the modern day, our gut microbiota is subjected to constant assault from eating processed foods, taking drugs & antibiotics, living with stress and usage of disinfectants. This depletion of gut microbes, called dysbiosis, compromises the integrity of the gut lining, causing intestinal permeability (often called “leaky gut”) through which toxins, pathogens and undigested food particles may leak into the blood stream, triggering responses from the immune system which eventually cause chronic inflammation to occur throughout the body. The chronic inflammation may in turn lead to the development of diseases such as metabolic disorders (type 2 diabetes, obesity, hypercholesterolemia, malnutrition), neurodevelopmental disorders (anxiety, depression, ADHD, ADD, autism spectrum disorder, dementia) and autoimmune disorders (irritable bowel disorder, eczema, food sensitivities and other allergies).

Fortunately, disrupted gut microbiota can be re-balanced, and subsequently health be restored. Studies have shown that beneficial bacteria are able to restore and maintain the health of intestinal gut walls, thus repairing the “leaky gut” syndrome and reducing inflammation in the body. 

Studies have shown that people suffering from neurodevelopmental disorders lack certain types of microbes in their gut[iv]. In another landmark study on brain development, a team from Caltech found that when the guts of autistic mice are rebalanced with specific bacteria, their autistic behaviours are reversed[v]. Numerous studies have also associated gut bacteria with influencing mood, behaviour and brain function[vi]

A DIET FRIENDLY TO GUT MICROBES CAN MAINTAIN GOOD MENTAL HEALTH

Eating foods which contribute to the well being of our gut microbes is an essential factor for maintaining mental health.

It is important to include in our diet foods rich in prebiotic and probiotics. Prebiotics are plant fibres that cannot be digested by the human body. They nourish the good bacteria (Bifidobacteria & Lactobacilli ) already present in the colon. Examples of foods rich in prebiotics are garlic, onions, asparagus, bananas, cabbage, beans and legumes.

Probiotics are “good” bacteria that help keep your digestive system healthy by controlling growth of harmful bacteria. Probiotics can be found in fermented foods such as kimchi, tempeh, yoghurt and sauerkraut. For example, in fresh cabbage, vitamin C is bound in the cellulose structure and various other molecules, and our digestive system is just not able to cleave it off and absorb it. Lots of it goes undigested and come out right out of the body. So despite the fact that cabbage may be very rich in vitamin C, a lot of it will not be able to absorb. But if that cabbage is fermented to make sauerkraut, all the vitamin C becomes bioavailable. The amount of bioavailable vitamin C in sauerkraut is 20 times higher than in the same helping of fresh cabbage. Probiotics can also be taken as supplements. However, not all probiotic supplements are specific for ADHD, and care must be taken to choose those which can survive and thrive in the gut environment.

[ii] Gut-brain link grabs neuroscientists, Nature, 12 Nov 2014.
Can be accessed at http://www.nature.com/news/gut-brain-link-grabs-neuroscientists-1.16316

[iii] Microbes help produce serotonin in gut, Caltech, 9 Apr 2015.
Can be accessed at https://www.caltech.edu/news/microbes-help-produce-serotonin-gut-46495

[iv] Study: Kids with autism have fewer kinds of gut bacteria, Autism Speaks, 3 Jul 2013.
Can be accessed at https://www.autismspeaks.org/science/science-news/study-kids-autism-have-fewer-kinds-gut-bacteria

[v] Bacterium can reverse autism-like behaviour in mice, Nature, 5 Dec 2013.
Can be accessed at http://www.nature.com/news/bacterium-can-reverse-autism-like-behaviour-in-mice-1.14308

[vi] The tantalizing links between gut microbes and the brain, Nature, 14 Oct 2015.
Can be accessed at http://www.nature.com/news/the-tantalizing-links-between-gut-microbes-and-the-brain-1.18557

This articles was first published in “I’m not naughty”, pp 8-9, issue 38, April 2016. This is a newsletter of SPARK, the society for the promotion of ADHD research and knowledge based in Singapore. Click here to view the original article and newsletter. 

How To Choose A Probiotic Supplement

In a perfect world, our brain and body will be able to get all the nutrients it needs from eating a healthy diet. Unfortunately, the modern world is far from perfect. The quality of our food supply is generally poor, and our brain and body are constantly subjected to environmental aggression. Hence, supplementing our existing diet with dietary supplements is necessary to ensure that we get optimal nutrition.

In our case, we are particularly interested in supplements which can help balance our gut microbiota and help maintain mental performance. Studies have shown that probiotics are one of the most effective supplements with such properties. Studies have shown that ingesting beneficial bacteria do significantly improve and protect intestinal cells. This in turn will help reduce the effect of the leaky gut, reduce inflammation, restore basic body functions and brain health.

Confusion in the marketplace

If you have jumped into the world of probiotic supplements, you would probably be very confused. There are many many products lining health food stores. Which supplements are best for you? Are the expensive ones worth paying for? Why is there so much conflicting information?

Not all probiotics are created equal

The truth is that not all probiotic supplements are equal. Some work very well, some work partially and some don’t work at all. Having worked on probiotics for the past 20 years, I will, in this post, help you to cut through all the marketing information, and present a checklist of what I consider to be important characteristics of the ideal probiotic supplement when making a purchase.

Probiotics must survive acidity. Firstly, they must be able to survive the acidity in the stomach, survive the intestinal environment with its mix of hostile microbes. If they cannot survive, they cannot do their work. This is very difficult to evaluate because it is linked to the way they are made. Many single strain bacteria are industrially produced in bioreactors using pure substrates, eg glucose. However, in nature, pure glucose do not exist. You find starch, rice, complex carbohydrates. Many of these bacteria do not know how to survive in the gut. The bacteria must go through special preparation to survive the digestive tract.

Big counts don’t matter. When you go the shop, you find probiotics which boast of large counts of bacteria. Do they matter? It depends. If they cannot survive the passage through the stomach, the counts don’t matter at all. But if they need these large numbers to ensure that some may sneak past the stomach into the intestine, then they need this huge army. But if the counts are small, but they can survive the gut, then it doesn’t matter because microbes double every 20 to 30 minutes.

Microbes work in communities, not in isolation. Microbes also do not and cannot work alone. Products which contain only 1 strain of bacteria may not be effective. There is a difference between blends and communities. Blended microbes consist of individually produced microbes mixed together while as community microbes grow up together. Blended microbes may produce erratic results because they may not grow together properly. Typically one strain will outgrow the others, in other works, instead of working together, they end up fighting. If the microbes grow together, they will complement and help each other, and adapt effectively as the environment changes.

Bacteria are very adaptable. Although 2 products may contain the same strain, the actual effectiveness may be very different. This is because microbes can be trained. Different microbes can be trained to trigger gene expressions differently, hence producing significantly different results. Microbes can be enriched to be more effectively for specific conditions. For example, ProVie G has been tested in hospital and found to be as effective as insulin in lowering blood glucose.

Good products give consistent results. Finally, from product to product, the probiotics must be consistent in effectiveness. For single strains and blends, this is relatively easy to achieve. But for communities, it is far from obvious as the complexity is mind boggling. Probiotics should produce effects which are repeatable and consistent.

Why My Brain Doesn’t Work Today?

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Finding it hard to get out of bed?

Struggling to concentrate? Can’t focus?

Forgetting simple details?

Feeling scattered or confused?

Can’t pull your thoughts together?

Mentally tired? Brain not working?

If so, you may be suffering from “brain fog”. And if brain fog occurs too often, it then becomes a real problem as it negatively affects our productivity at work and vitality as a person.

Although not an official term, brain fog can be defined as a loss of mental clarity, difficulty concentrating and forgetfulness. And don’t blame your brain for the condition – brain fog is actually caused by inflammation and malfunctioning of your second brain (aka the digestive tract and gut microbiota).

What do you mean?  I have a “Second Brain”?

We all know that the brain is a very important organ in our body which controls every function, thought and reflex in our bodies. However, an increasing number of scientists and researchers have discovered that our bodies contain a separate nervous system located in our gut and this nervous system controls our bodies in far more ways than we might realise – and most people do not even have any idea about it.

This nervous system, called the enteric nervous system (ENS) is embedded in the wall of our gut and contains more nerve endings than the spinal cord. To describe the complexity and importance of this extensive meshed network of nerve endings in the gut, Dr Michael D. Gershon, professor at the New York Columbia University, coined the term “Second Brain”. All along, we know that the second brain plays an important part in controlling digestion of the food we eat. But new research is now showing that it plays an even more important role in our physical and mental health.

But the research work doesn’t end with just the discovery of the second brain. What is even more astonishing is that the gut contains trillions of microbes residing in our digestive tract. And these microbes affect our physical and mental health in many ways.

For example, the gut microbes produce 50% of the dopamine and 90% of the serotonin, two feel-good brain hormones, in our body. This in turn has a surprising effect on our mood and behavior. In fact, some studies have shown that eating yoghurt with healthy bacteria produced measurable decrease in individuals’ depression and anxiety levels, and increase in resilience from negative emotions making us more forgiving and social.

Another example, you arrived late for work, missed an important meeting and your boss was mad at you. Come break time, you couldn’t help yourself but head straight for the chocolate bar. It happens, at times of stress, our brain prompts us to seek out comfort foods. That much is known. What you don’t realise, though, it is actually not your brain in your head which made the decision but the microbes in your second brain which are responsible for the decision.

Introducing The Microbiome

What are microbes? Microbes are living things which are so tiny that we can only see them through a microscope. They are found all around us. When we mention microorganisms, many of us associate them with germs; germs that cause infectious diseases such as sore throats, flu, pneumonia and tuberculosis. We believe they are bad and we do all we can to kill them. We become obsessed with cleanliness: we shower ourselves with anti-bacterial soap, rub our hands with sanitizers, take antibiotics and so on. Yet, most microbes are not bad guys. In fact, many live in harmony with us and perform many functions vital to our survivability.

Through our many years of research, we found out that our bodies are home to trillions of microbes, many of which are living inside our gut. Collectively, they are called the “microbiome”. They actually outnumber the cells in our body by 1.3 times and are very important for our health.

Why do we have so many microbes? We need them because they protect our bodies from pathogens and infection; they help prime & fine tune our immunity system; they help in food digestion; they help to harvest energy from food that we eat; they also help synthesize essential nutrients eg. vitamin B12. In short, the microbes in our gut are vital for our metabolic health. Scientists are so impressed with the microbiome that it is often called the “forgotten” organ.

The Gut-Microbe Link To Mental Health

What is not so obvious is that the gut microbiome also affects our mental health.

Gut microbes can manipulate us via the second brain. For example, they can influence the food we eat. If our diet consists of sugars and fats, we are encouraging the growth of sugar & fat loving microbes in our gut. To survive, they will make us crave for sugary and fatty foods which in turn will ensure their survival in our gut.

Numerous studies have also shown that in more extreme cases, the gut microbiota is linked to brain development disorders such as anxiety, depression, ADD, ADHD, autism, learning challenges, dementia and even Alzheimer’s disease. A study from the Karolinska Institute of Sweden showed that gut microbiota can directly influence the brain. In the absence of certain good bacteria and presence of bad, inflammation can occur in the brain.

So, what is the underlying cause of brain fog?

When we are healthy, our body produces a protein in our digestive tract called zonulin. Zonulin helps to regulate the tight junctions between cells in our digestive tract, which keeps undigested food particles, pathogens and gut microbes inside the intestine.

However, when the gut microbiota becomes stressed and imbalanced because of diet, lifestyle or stress, our body overproduces zonulin which instead cause the tight junctions of the cells in our digestive tract to break apart. The intestinal wall weakens, allowing undigested food, live bacteria and toxins to leak through the intestinal wall and cross into the blood stream, developing a condition called the “leaky gut syndrome”.

As these substances aren’t supposed to be in our blood stream, our body triggers an immune response to help fight off these foreign invaders. As the immune system is meant to help us fight illness and disease, it attacks both the invading foreign bodies and healthy cells, causing inflammation to occur in the digestive tract. This inflammation may eventually spread to other parts of our body including our brain, thus causing the “fogginess” and slowed cognitive function associated with brain fog.

In fact, studies show that the leaky gut syndrome doesn’t just contribute to brain fog, but it is also associated with a host of more serious mental disorders such as depression, anxiety, ADHD, dementia and Alzheimer’s disease.

Triggers of the leaky gut

There are two known triggers which are involved the excessive release of zonulin which in turn leads to the leaky gut syndrome.

The first is presence of gluten in the digestive tract. Gluten is a complex protein found in many foods but cannot be digested by the body. Gluten fragments in the digestive tract can instigate cells to release zonulin.

The second trigger is the gut microbiota. The microbiota can become imbalanced, a condition which is called dysbiosis, because of bad diet, unhealthy lifestyle, stress, inappropriate use of medicine and so on.  Or the microbiota may not be distributed the way it should be, for example, in a condition called small intestine bacterial overgrowth (SIBO), microbes which are supposed to be in the colon are present instead in the small intestine. This is a very strong stimulus for the excessive release of zonulin and cause of the leaky gut.

Mitigating the leaky gut

Fortunately, we can do something to mitigate the triggers of excessive zonulin release and the leaky gut syndrome. In fact, there are many practical things we can do to cultivate a balanced gut microbiota to keep the zonulin in check, which in turn develops a healthy gut and improves our mental performance.

The key factors which impact the balance of our gut microbiota are genetics, age, the way we were born (natural or C-section), environment, diet, lifestyle and use of medicines especially antibiotics. Factors associated with genetics, type of birth and age cannot be changed, so there is little we can do about them. However, factors like environment, diet, lifestyle and use of antibiotics are within our control, and with a little will power, we can make the changes that matter.

In our subsequent posts, we will deft into the details of the do’s and don’ts of how to strengthen our gut health and maintain a healthy brain. Remember, how well our brain performs is principally influenced by our gut.

Conclusion

Science has established the link between the gut microbiota and our mental health. It is hence important to ensure that we maintain a healthy gut microbiota, so that our brain can function properly and we can continue to maintain mental performance. In our following articles, we will see the factors influencing our gut microbiota and learn how to care for our gut microbiota.

Bitter Gourd and Moringa Oleifera: Two Super Plants for Glucose, Cholesterol and Blood Pressure Support

Plants have a long traditional history for use in the treatment of metabolic abnormalies. Two plants in particular have stood out for their potent healing effects on metabolic syndrome. They are the bitter gourd (momordica charanti) aka bitter melon and moringa (moringa oleifera).

Bitter Gourd

Bitter gourd, commonly used as a fruity vegetable in many Asian countries, is also known for its healing properties for many conditions.

  • Glucose Support. The fruit contains at least three active substances for glucose support. They include charantin, vicine and an insulin-like compound known as polypeptide-p. These substances either work individually or together to provide glucose support. It also contains lectins or non-digestible sugar-binding proteins, which help reduce the amount of sugar absorbed by the digestive system [1].
  • Cholesterol Support. Bitter gourd helps in inhibiting conversion of sugar into fat and stimulating breakdown of fat in the body. The high content of fibre helps in digestion and maintenance of a normal level of triglycerides and cholesterol in the body [2].
  • Blood Pressure Support. In a 2011 animal study published in the Journal of Medicinal Food, ingesting bitter gourd is shown to lower blood pressure [3].
  • Others. Bitter gourd helps to combat inflammation and can be beneficial in treating conditions such as high uric acid, ulcers, colitis, constipation and gastrointestinal upset. Taking bitter gourd supplements or eating it promotes proper digestion due to its nutritional makeup, particularly the amount of fiber found in the vegetable.

Moringa Oleifera

Moringa is a plant that is native to the sub-Himalayan areas of the Indian subcontinent. Today, it can be found in the tropics and in many Southeast Asian countries. The leaves, bark, flowers, fruit, seeds, and root are used to make medicine. The moringa tree is also commonly called “horseradish tree,” since its roots taste similar to horseradish root when raw.

  • Glucose Support. A recent study published in the March 2014 issue of Acta Histochemica, however, suggests that moringa, through its rich vitamin, mineral and antioxidant contents, can effectively provide glucose support [4].
  • Cholesterol Support. Recent animal studies showed the positive cardiovascular attributes of Moringa. In one study, Moringa was found to be comparable to statins (a widely used class of cholesterol – and lipid-lowering drug) in suppressing the initiation and propagation of lipid peroxidation and suppression of atherosclerosis formation [5]. Another study found Moringa to have hypolipidaemic effect and lower cholesterol [6].
  • Blood Pressure Support. When consumed appropriately, moringa also has beneficial effects on the blood pressure in humans. Moringa contains high amounts of Potassium, Vitamin E, Calcium, Magnesium and  Zinc – all important nutrients for blood pressure support [7].
  • Others. According to a study, moringa also exhibits anti-inflammatory and anti-arthritic properties [8].

Related Post

> A Microbiome Approach for Glucose and Cholesterol Control using Fermented Bitter Gourd and Moringa

References

[1] Bitter Melon (Momordica charantia) Reduces Adiposity, Lowers Serum Insulin and Normalizes Glucose Tolerance in Rats Fed a High Fat Diet, J. Nutri April 1, 2003 vol 133 no. 4 1088-1093.

[2] Bitter melon helps maintain normal glucose levels and reduce total cholesterol and triglycerides.

[3] Bitter Melon Extracts in Diabetic and Normal Rats Favorably Influence Blood Glucose and Blood Pressure Regulation

[4] Moringa oleifera can help treat diabetes, study finds.

[5] Hypocholesterolemic effects of crude extract of leaf of Moringa oleifera Lam in high-fat diet fed wistar rats.

[6] Effect of fruits of Moringa oleifera on the lipid profile of normal and hypercholesterolaemic rabbits.

[7] How is High Blood Pressure and Moringa connected.

[8] Antiarthritic, anti-inflammatory activity of Moringa peregrina seed oil and leaves in Freund’s complete adjuvant-induced arthritis in rats.