The gut is the most under-rated organ in the human body, which is extraordinary when you consider that it accounts for two-thirds of our immune system, extracts energy from every food we feed it, and produces more than twenty unique hormones.

This organ that is responsible for little brown heaps, and unbidden sounds and smells is currently forcing researchers to rethink its role.

We humans have known since time immemorial something that science is only now discovering: our gut is responsible in no small measure for how we feel. We are ‘scared shitless’ or we can be ‘pooing our pants’ with fear. We can’t get our ‘arse in gear’ if we don’t manage to complete a job. We ‘swallow’ our disappointment or pride and need time to ‘digest’ information or defeat.

When we fall in love we get ‘butterflies in our tummy’ and we often rely on our ‘gut feeling’ when it comes to certain situations or people. Our self is not only created in our head but also in our gut and scientific research is now beginning to confirm this at a biological level. Therefore it is paramount that we do everything to keep our gut happy and our digestion running smoothly.

We’ve all heard the adage ‘You are what you eat’. Everything we eat comes from living things, and living things are made up of three basic ingredients, sugar molecules (carbohydrates), amino acids (proteins) and fats. The form in which you take each of these things in is very important.

In general, the more complex the ingredient, in other words the closer it is to its natural state the more beneficial it is for us. A clear example of this is sugar. The sugar contained in a slice of wholemeal brown bread is broken down slowly and released into our system bit by bit, compared to the sugar explosion caused by a slice of white bread.

This explosion causes our body to pump out large amounts of various hormones, most importantly, insulin, to restore a healthy balance once more. Sugar is the only substance our body can readily turn into fat with little effort.

Proteins are made up of nutritional building blocks called amino acids. There are twenty of them and we humans use them to build many substances, not least of which is our DNA. This explains why everything nature produces that we can eat contains protein.

Once again, we need a variety of sources to keep us healthy. Most of our protein should come from plant-based sources and be supplemented with small amounts of animal proteins.

Fat is the most efficient and valuable of all food particles, packing twice as much energy per gram as carbohydrates or proteins. We use fat to coat our nerve cells, some of our most important hormones are made of fat and the membrane of every cell in our body is made largely of fat.

However, the source of fat that we put into our bodies is critical and should weigh heavily towards plant and nut based oils. Such oils contain anti-inflammatory substances which have an effect much like ibuprofen or aspirin, while animal fats found in meat and milk contain a substance that is converted in our bodies into neurotransmitters involved in the sensation of pain.

So, giving the gut good quality fuel to work with is certainly going to help keep it, and therefore you, happy. One of the ways that healthy food achieves this is by keeping the gut microbiome happy, in other words, by nourishing our gut bacteria. Our guts’ microbiome can weigh up to two kilos and contains about 100 trillion bacteria.

This community of microbes crack open indigestible foodstuffs for us, supply the gut with energy, manufacture vitamins, break down toxins and medications, and train our immune system. Different bacteria manufacture different substances: acids, gases, fats, bacteria are tiny factories. We know that gut bacteria are responsible for blood groups, and that harmful bacteria cause diarrhoea. What we don’t know is what all this means for each individual and research into our gut microbiome is only in its infancy.

We each have our own unique ecosystem, which starts with the bacteria we inherit from our mother during our birth and subsequent breastfeeding, the bacteria we are exposed to from the skin to skin contact of our family members and our environment. This ecosystem takes years to develop and then needs to be kept in balance for the rest of our lives and it goes some way to explaining why the same diet doesn’t suit everyone and why we each need to discover what works best for us and our system.

Our digestive system is as amazing and complex as our brain. Its’ role goes far beyond allowing us to poo. It plays a part in obesity, allergies, depression and even Alzheimer’s. It behoves us to treat it with respect, nourish it and not abuse it.