As a gut health expert, everyday I witness the strong connection between the brain and the gut – known as the gut-brain axis.

In fact, most of my clients seeking help with their digestive issues also report brain fog, poor memory and other brain-related complaints.

From my experience working with hundreds of people with digestive issues, I know that improving gut health will have a positive impact on brain function, often completely eliminating brain-related issues.

So improving your gut health should be your first step!

Take your first step to a happier, healthier gut today with our Quick Start Guide. It’s FREE! Get your FREE QuickStart Guide.

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However, let’s not forget that this communication goes both ways… the brain also affects the gut.

The main communication between your gut and your brain happens through the vagus nerve. I talk in great length about the vagus nerve here, but today, I want to focus on the neurotransmitter that is necessary for the effective functioning of the vagus nerve: ACETYLCHOLINE

Acetylcholine is a neurotransmitter that is needed for many functions in the body, from learning and memory, to digestion, inflammation and so much more.



Acetylcholine deficiency has a major impact on learning and memory, especially short-term memory.

What does it feel like when you’re deficient in acetylcholine?

  • Those “tip of the tongue” moments are happening more often than usual.
  • You struggle to do simple math problems in your head.
  • You lose your train of thought during conversations.
  • You can’t follow plots in movies and books.
  • You can’t recall something you just read.
  • You often misplace everyday items like keys, phone and glasses.
  • You have to write everything down in case you forget
  • Your sense of direction is poor and you frequently get lost.
  • You have poor muscle tone and find it hard to exercise.


Many of the symptoms of acetylcholine deficiency are typical of what we joke about as ‘senior moments’.



Acetylcholine is also necessary for the activation of the vagus nerve, which in turns stimulates the parasympathetic nervous system. More about the vagus nerve here.



The parasympathetic system is also called the rest and digest response in the body and hence is involved in pretty much every aspect of digestion, including peristalsis (movement of food/stool through the digestive tract), stomach acid production, opening of the pyloric sphincter at the bottom of the stomach, gall bladder function, some pancreatic function, and opening of the Sphincter of Oddi (which allows bile and pancreatic enzymes to pass into the intestines).

Low acetylcholine levels can result in chronic constipation (especially constipation caused by slow transit time) and/or gastroparesis (foods sitting in your stomach for hours) with poor digestion and poor absorption of critical nutrients.

It also affects the functioning of the ileocecal valve, which in my experience is often at play in SIBO (small intestinal bacterial overgrowth).

Fun fact:

Nicotine (via nicotinic acetylcholine receptors) helps gut movement. This is why when people stop smoking, they often get constipation. I don’t recommend you start smoking to help with constipation though 😉



Most of those symptoms are also related to the vagus nerve and parasympathetic response.

  1. Weakness: Acetylcholine is needed by your muscles and without it, weakness can occur, especially after exercise. The muscles may work for a while, then exhaust their supply of acetylcholine, leading to extreme fatigue.
  2. Pain: Increasing acetylcholine reduces pain.
  3. Poor dream recall: Another interesting fact is that most dreams occur during rapid eye movement, or REM sleep, when acetylcholine levels are high. So if you are not dreaming, it might indicate that you do not have enough acetylcholine. People with low Vitamin B-6 don’t remember their dreams either.
  4. Dry eyes: Acetylcholine is required by the lacrimal gland to produce tears. When levels of acetylcholine are low, dry, painful eyes can result, and they can be resistant to treatment unless acetylcholine levels are restored.
  5. Orthostatic hypotension: Low acetylcholine levels result in low blood pressure when standing, which causes dizziness and weakness when standing.
  6. Flushing: Low acetylcholine levels can cause episodes of flushing (redness), and the face, neck and other parts of the body may appear flushed. This can be misdiagnosed as rosacea or mast cell activation.
  7. Emotional instability: People with low acetylcholine levels will often suffer from the inability to cope with their emotions. Their emotional state can be unpredictable.
  8. Chronic inflammation: Because acetylcholine is needed by the vagus nerve to bring you into the parasympathetic state (the anti-inflammatory pathway of the body), low levels contribute to consistently high levels of inflammation.
  9. Fast heart rate: Fast heart rate (tachycardia) can occur because the parasympathetic nervous system does not have enough acetylcholine to allow slowing of the heart by the vagus nerve. The vagus nerve uses acetylcholine to stimulate the sinoatrial node of the heart, resulting in the slowing of the heart rate.
  10. Large pupils: Pupil size is a function of the balance between the sympathetic nervous system (resulting in large pupils) and parasympathetic nervous system (resulting in small pupils). When this balance is upset by low acetylcholine, the sympathetic nervous system over-rides the parasympathetic nervous system, resulting in large pupils. Large pupils result in light sensitivity and can cause blurred vision when looking up close.
  11. Dr Diana Driscoll also mentions a possible connection with low acetylcholine and POTS/EDS, Chronic fatigue Syndrome, chronic Lyme disease and gastroparesis.




The daily recommended intake of choline is around 425 mg for women and 550 mg for men.

The best food source by far is egg yolks (each contains about 150mg of choline).

Other food sources include liver, beef, shrimp and high-fat dairy.

Virtually all animal foods contain choline (although none come close to egg yolk).

** Getting adequate choline is a challenge for anyone following a low-fat or vegan diet.

Green tea (and also other teas) can inhibit enzymes that break down acetylcholine, hence making more available for your body to utilise.



Phosphatidylcholine: also great to improve bile flow and fat digestion. We recommend Seeking Health’s PC as it’s derived from sunflower instead of soy. Get it here in Australia and here in the USA.

Phosphatidylserine (300mg): helps make better brain cell membranes. It’s especially useful for people with high stress/ high cortisol(it will help reduce it) or difficulty falling asleep. Get it here in Australia and here in the USA.

Huperzine-A: Acts by slowing the breakdown of acetylcholine.

Alpha GPC: Of all the choline-based supplements available, alpha GPC (L-alpha-glycerylphosphorylcholine) is considered one of the best form for raising acetylcholine levels. It’s well absorbed in the gut and can readily enter the brain.

Panthothenic acid (Vitamin B5)



It’s also important to be aware that a surprising number of drugs act as anti-cholinergic (which means that they block the action of acetylcholine in the body), both prescription and over-the-counter (OTC).

Before taking a supplement to increase your acetylcholine, it’s worth taking a look at all of the medications you are taking to see if any of those act as anti-cholinergic.

Here are a few examples:

  • Anti-histamine drugs like Benadryl and Claritin
  • Anti-acid medication like Peptide and Zantac
  • Some anti-hypertensive drugs



Even if you already have good brain function, you can support your acetylcholine to improve your focus, concentration and memory, especially in times of higher demands, like studying for exams, etc.

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