“Think of having ADHD in this way… You have a Ferrari’s brain – but have Chevy’s brakes”

Within the Gut & Brain series, these 2 fascinating and complex organs in the body actually interact together forming what we call today the ‘Gut-Brain Axis’. Along this axis, the gut and brain communicate and their language is in the form of neurotransmitters, hormones, immune cells and so on, this axis also works both ways (bidirectional) the brain impacts the gut as will the gut influence the brain.

While this may seem complicated, and it is complicated, there is already good evidence about how each organ affects the other and also on what we can do to influence any issues along this pathway in either direction. There is evidence that some neurological conditions are influenced by the gut microbiome, for instance, anxiety, depression, Alzheimer’s and Parkinson’s all have links with the gut, and while improving the gut is not a cure-all, it is an area where we can work on to improve our health.

In this piece, we are going to cover both Attention Deficit Disorder (ADD) and Attention-Deficit/Hyperactivity Disorder (ADHD), in particular looking at some of the nutrition and lifestyle changes which can improve these by working on this axis. Human Performance Hub’s founder, Roan talked with fellow coach and friend Joel to discuss some of Roan’s experiences with ADHD in his adolescence and to provide knowledge and advice about what you can do nutritionally and through lifestyle. Here’s what happened…

Briefly, what are they?

Firstly, we shouldn’t stigmatise any mental health topic, instead, look at what’s occurring and what we can do to improve things.

Attention Deficit Disorder (ADD) and Attention-Deficit/Hyperactivity Disorder (ADHD) characterise a series of traits including struggle to maintain attention, show impulsivity, constant activity or unable to relax and be inactive. Ultimately, they are different terms for the same set of behaviour traits.

“The kidney does not care if you call it sick, but the mind does…the best way to think of ADD is as a collection of traits that define a way of being in the world”.

Edward Hallowell – psychiatrist and author

So Roan, how have you experienced ADHD in the past?

My experience has been right through my younger years up until my late teens. I don’t think it is one of those things that suddenly goes away, I look at understanding how to manage it.

We find that 65% of children who have ADHD still experience some of the symptoms by age 25, so it varies between people in terms of how much it affects you, what traits you show and how it improves over time (2).

What have been the symptoms and other things you have noticed from this?

Well, as a kid I wouldn’t be able to tell you what the symptoms were, as I was thinking everything was normal while running around, causing chaos. I would say the main stand out symptom would be the inability to concentrate fully for long and to take in information. I’m sure my mother will gladly add to this!

Environmental factors, like diet, do play a role, despite what some people in conventional medicine might say. This is why things got a lot better as life went on because my knowledge of nutrition and supplementation grew.

There were some environmental-lifestyle factors that contributed to the symptom/s when I was young. Poor or the wrong type of diet for me (having gluten and dairy). Excess exposure to antibiotics.

Acetaminophen or paracetamol (this would be due to the number of operations I had on my ears as baby/child). Acetaminophen is used quite a bit in kids, and there’s some slightly concerning research suggesting that it can be a contributor to ADHD. If these environmental stimuli happen at critical times during brain development early in a kid’s life, then they can have long-lasting effects.

How has it affected daily life and your health?

It most definitely slowed down my learning ability when growing up to understand language and process information. With regards to my health, I have to constantly support my gut and my body’s detoxification with good nutrition choices and supplementation.

For others, however, it may affect their daily life in terms of restlessness and disruptive behaviour, it affects both the person and those around them in many ways.

So what are some of the causes of your research into ADHD?

There is no real single root cause. There’s a broad range of things which I think are the most likely contributing factors to ADHD at this point with my understanding. We could think of it as a kind of gut-brain disorder which is turning out to be valid with a lot of behavioural and even psychiatric conditions like depression, ADHD, and an autism spectrum disorder.

Even Parkinson’s and Alzheimer’s now are increasingly thought to have a gut-brain element, this is not too surprising given what we’ve come to understand in terms of the gut-brain axis.

The areas that I have investigated and have had a positive outcome are:

Nutrient status.

The first thing to look at, of course, would be nutrient status. That means ensuring a nutrient-dense diet, adequate amounts of zinc, copper, choline, B12, iron, folate, and vitamin A, which I have been getting through the right multivitamin and been taking B vitamin complex shots. Vitamin D status is crucial; I see this as my craving for sun exposure.

Toxin exposure.

Even in the conventional world, they have recognised that toxic exposure is a contributor to ADHD, and there’s certainly plenty of research to support that. So reducing exposure to toxins in food and the environment in general and then implementing some safe detox and making sure the detox systems are working correctly is very important.

This other reason I like Chlorella, as I have seen great results on myself, not been too aggressive but been effective in supporting my GUT and my body’s detoxification. This is another reason why I am sensitive to lousy coffee, as we now know that coffee is the most exposed to the most pesticides.

Chlorella Human Performance Hub

Heavy metals.

Any kid who’s dealing with ADHD, I would test them for heavy metals, particularly mercury, arsenic, lead, and cadmium which can be contributors, and unfortunately, high levels of these in kids are quite common. Heavy metals are a tricky one, as I have been tested a few times, with different methods of testing.

This is one of the main reasons I continue to work on my detoxification, as all the tests have shown the presence of heavy metals. Again, I bring this down to being in and out of the hospital in the very early stages of my life.

I would suggest if people are interested in this, would be to find an excellent functional medicine practitioner as this is not a simple thing to oversee.

Gut microbiome.

This is a significant factor in my eyes as I talk from experience, for all of the reasons that I mentioned earlier/above. We know that disrupted gut microbiome can cause a lot of adverse effects on the brain.

We want to identify potential issues like fungal overgrowth, parasites, bacterial pathogens, and SIBO and treat those. I like to use and rotate the following products for anti-microbial support.

Human Performance Hub GI Microbial 


G.I Microbial is a botanical blend of ingredients that helps to diversify the gut microbiome to maximise digestive health. Fulled by Designs for Health GI Microb – X


Other products I have used with a good results with clients are, Garlic extract – Allicillin, Designs for Health, Oil of Oregano, Designs for Health, Olive Leaf Extract   Since olive leaf can support many of the body’s systems, from the nervous system (brain) to the immune system (defence), it is a good supplement to include as an all-rounder to support your health in many aspects.


Talking from personal experience and as this was/is a big thing in my life, I have asked a lot of professionals in the functional medicine world, you want to reduce exposure to antibiotics as much as possible.

Of course, antibiotics can be lifesaving and necessary where needed. I’m not suggesting they should never be used, but I’m suggesting that they should be used judiciously and wisely.

Things like ear infections, which is when I was in and out of the hospital so many times in my younger years, doctors may often prescribe antibiotics. Still, if you look at the research on ear infections, many of them are viral, and many of them are self-limiting, which means they’ll heal with or without antibiotics at the same rate.

The reason we don’t like poor use and overuse of antibiotics is they literally destroy gut bacteria, and they don’t selectively eradicate bad bacteria they also remove the good bacteria too. This then worsens the gut microbiome


It may be worth trying, more specifically, above and beyond just a nutrient-dense diet, a GAPS or a ketogenic type of approach to food. In some cases, I think with ADHD you get a disrupted gut microbiota that’s producing these chemicals that affect brain function and restricting carbohydrate.

Mainly starch can be beneficial in resetting the gut microbiota and reducing the production of these chemicals. You’d want to do that under the supervision of somebody who knows how to work with these diets because there are some other considerations with kids where you want to make sure that they’re getting all of the nutrients that they need and you’re doing it in a way that it’s safe.

Find a professional who is focused on this subject, and I only wish we had the research and the number of people that are aware of this now when I was growing up.

For further reading, I would recommend a book called gut and psychology syndrome (GAPS)  by  Natasha Campbell-McBride.

What neurotransmitters are involved and how do they work?

Many neurotransmitters could be involved. Most research points towards a deficiency in dopamine (7), which is the brain’s chemical messenger of reward, so if we lack sufficient dopamine we may exhibit behaviours which are restless, risky, dangerous, and so on in order to raise dopamine. However, it is not a case of raising dopamine and that is your cure.

The gut makes neurotransmitters and other chemicals which talk with the brain (6), so we need to improve what goes on in the gut, and this can help.

What nutritional changes have been able to help?

No gluten and no dairy are the big game-changers, both of these don’t help the gut, by removing gluten and dairy you improve any ‘leaky gut’ and inflammatory issues and then this obviously influences how the gut talks to the brain with better chemical production in the gut.

What supplementation is beneficial?

I would suggest covering the basics first, this reduces the chance for any nutrient deficiencies.

  • Fish oil – great for anti-inflammatory support and also for neurological health.
  • D3+Vit K both of these greatly help the brain, and if you don’t get enough sun…
  • Zinc and Magnesium both support the nervous system and help with recovery. 
  • Some form of green algae – I would suggest starting with Chlorenergy, this is because it helps to diversify gut bacteria, provides B vitamins and also removes the harmful heavy metals and toxins. 

The rest will need to be done on a case by case basis, but usually, I would suggest looking along the lines of the Brain, GUT and detoxification support.

Here are some further articles:


What you eat and take has an impact on the body, and this article highlights that some conditions and behaviours are somewhat influenced by the nutrients we get. 

Nutrients influence the chemical signalling of the brain and the gut’s signalling too, so to support your behavioural, neurological and mental wellbeing it is necessary to ensure you cover your bases and get essential nutrients in your diet. It won’t change you as a person, it won’t cure anything, but it can provide the extra pieces to the puzzle which get you that bit closer to your healthiest and best self. 

Plus, supporting your gut and brain will help other things like energy, sleep, focus and body composition in various ways. 

If you need further advice or programming then get in touch. 


We’re always here to help. If you have any questions or would like advice about supplements, nutrition, or training, please book in for a consultation.

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Further Reading:

  1. The Simplified Guide to the Gut-Brain Axis – How the Gut Talks to the Brain 
  2. NHS – ADHD Symptoms  
  3. Diversity of the Human Intestinal Microbial Flora 
  4. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems
  5. Gut Microbiota and Brain Function: An Evolving Field in Neuroscience
  6. From gut dysbiosis to altered brain function and mental illness: mechanisms and pathways
  7. Attention-deficit-hyperactivity disorder and reward deficiency syndrome 
  8. Antibiotics alter the gut microbiome