A Novice's Guide to the Gut-Brain Connection

Let’s take a brief skip through the Gastrointestinal (GI) tract and the digestive system: the GI tract is a tube that runs from your mouth to your bottom and can be considered as the interface between the outside world which offers us food/drink for nourishment, but also harbours potentially harmful bacteria, pollutants and toxins. To survive and thrive, we need to filter out and utilise the good components, whilst keeping harmful elements at bay or discarding them. The GI tract is where the action happens, as it is home to:

  1. The various organs that comprise our digestive system, which work together to convert food into energy and basic nutrients that feed the entire body and provide the building blocks for structures and repair
  2. 80% of our immune-system which is vigilant at defending us from pathogens and other invaders
  3. The enteric nervous system (ENS), often called ‘the second brain’, as it can function independently of our brain and spinal cord

The gut is also home to some of the same neurotransmitters, or ‘brain chemicals’, that are active in the brain including dopamine, noradrenaline, most of our serotonin (chemicals that help keep our moods balanced) as well as several other types of messengers that influence our mood, memory, cognition and control various physical processes such as gut motility.
— Lisa McConnell, Nutritional Therapist

All diseases begin in the gut
Considering that the above is just a whirlwind tour of what is going on the gut, it is easy to see how the theory ‘all disease begins in the gut’ came to being. It should come as no surprise when your physiotherapist, endocrinologist, neurologist, psychiatrist, gynaecologist, dermatologist, dentist or any medical professional starts asking questions about your digestive health and diet in relation to your mental well-being, chronic pain, neurological symptoms, hormonal imbalances, or any health concern for that matter.

Increasingly candidiasis (yeast overgrowth), parasitic infections, dysbiosis (bacterial imbalances), ‘leaky gut’ (permeable gut lining), SIBO (small intestinal bacterial overgrowth) and lack of hydrochloric acid production and/or digestive enzymes may be more commonly linked to a myriad of symptoms such as food sensitivities, nutrient deficiencies, eczema/psoriasis, frequent infections, attention deficit disorders and autism, brain fog, fatigue, depression and memory loss: an entire array of auto-immune, neurological and inflammatory conditions could be due to gut imbalance.

Whilst the ENS (enteric nervous system or “second brain”) partially functions independently, it is part of a communication network called the gut-brain axis, which facilitates continuous two-way communication between the gut and the brain, as well as branching out to other parts of the body.

An uncommon case of coffee and shoulder pain
Approaches such as integrative and functional medicine take these associations a step further: fellow functional medicine practitioner, physiotherapist and founder of Integrative Physio, Matthew Winter, explained (much to the bemusement of his client) regarding the seemingly strange association between drinking coffee and recurring flare-ups of shoulder pain: “the Vagus nerve runs between the brain and the gut, but has little tributaries that branch out into the shoulder, so if the gut is too acidic or otherwise irritated, the vagus nerve is likely to be irritated too, inflicting pain in an unexpected location as a signal that something is out of balance.”

So, next time you are convinced that you must be the subject of a design flaw or you can’t quite put your finger on the source of your malaise (there may be a few) – listen to your gut! Get in tune with the signal that it is time to cleanse, revitalise and rebalance gut ecology.


More about Lisa McConnell, Nutritional Therapist
Nutritional Therapy BSc (Hons), CNHC registered
Certified GAPS* Practitioner
Member of BANT, IFM, RSM

Training and practicing on the basis of Functional Medicine enables Lisa to work with all types of health conditions though she has a particular interest in adult Attention Deficit Disorder (adult ADD) and mental health. She is keen to promote personalised health care and zealous about keeping abreast of new research/advances in nutrition/natural medicine, particularly in the areas of nutrigenomics, the human microbiome, sports nutrition and cancer care. More at www.iphysio.sg