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Gut health - why is it so important & 15 ways you can improve it

What we choose to consume and put into our digestive system, directly impacts gut health and health outcomes.

Simply put:

ü You are what you digest

ü You are what you absorb

ü You are what you don’t excrete

A healthy digestive system or healthy gut should be able to digest foods, absorb nutrients and effectively excrete wastes from the body.

How does our gut or digestive system impact health outcomes?

Many people aren’t aware that 70% of our immune system resides in our gut or digestive system (DS), and the collection of immune cells in the gut wall forms part of the first line of defence against ingested pathogens. The majority of these white blood cells are in the intestines, which is where absorption occurs, so as a result, this area is constantly being challenged by pathogens.

Our gastrointestinal tract (GIT) contains up to 100 million neurons or nerve cells. They have been termed the ‘brain of the gut’. These nerves are part of either the parasympathetic (rest and digest) or sympathetic (fight or flight) nervous system.

The parasympathetic nervous system is active during times of rest, whilst the sympathetic becomes active under times of stress. Why is this relevant for gut health? Our parasympathetic nervous system activity increases muscular activity in the GIT and encourages digestion, whilst sympathetic stimulation stops GIT contraction because the body is busy focusing on dealing with ‘fight or flight’ mode, effectively saving life, de-focusing non-priority body systems. This, in turn, compromises digestion and causes symptoms such as gas and bloating during times of chronic stress.

The large intestine contains more than 100 trillion bacteria or micro-flora which perform the following essential bodily functions:

- The final stages of nutrient extraction from carbohydrates

- The production of vitamins (e.g., the bacteria E. coli produces vitamin K, which is important for blood clotting)

- Preventing other bacteria from causing intestinal disease by blocking attachment sites

- The ongoing development of the immune system (white blood cells are said to be ‘learning’).

The term “gut microbiome” refers to microorganisms in your intestines. Each person has about 200 different species of bacteria, viruses, and fungi in their digestive tract.

Therefore, it is essential to maintain the health of the digestive system to support and enhance immunity.

The role of microorganisms in gut health

We know that there are some microorganisms that are harmful to our health, but the fact is that there are many that are incredibly beneficial and even necessary for a healthy gut, mind, and body.

We are learning a lot more about the gut microbiome, the role of certain foods and nutrients in helping to support the development of healthy gut bacteria, and that having a broad variety of gut bacteria may help to reduce the risk of developing chronic diseases, such as diabetes, arthritis, and inflammatory bowel disease.

It is an incredibly complex area, but recent studies show a link between gut health and mental health, autoimmune disease and the immune system, cardiovascular disease, cancer, and endocrine disorders.

How is the health of the digestive system impacted?

Our DS and gut health are directly impacted by what we choose to consume and put in our bodies.

There are various substances and lifestyle choices which negatively affect and damage the health of the gut:

-Junk and fast food

-Fizzy or sugary drinks

-Pro-inflammatory foods (e.g., dairy, sugar, gluten)

-Pesticides in/on food

-Food colouring's


-Heavy metal toxins

-Drugs, e.g., antibiotics (which destroy the healthy gut bacteria)

-Vaccine ingredients (e.g., aluminium and formaldehyde)

-Ongoing and consistently high-stress levels

-Not getting enough sleep

-Eating a Western diet typically high in processed and high sugar foods

Another interesting concept is that it is thought that infants are born with a sterile GIT, up until the infant ingests vaginal and faecal microflora at delivery/birth, which is further enhanced by breastfeeding, building the baby’s immunity.

Signs of an unhealthy gut

If any of these resonate with you, then it could be time to make some dietary changes to address your gut health. Be aware that there may be other causes, and you should always check with your doctor first.

1. Unintended weight changes – if, without any proactive intention to gain or lose weight, you notice your weight changing, it could be due to an imbalanced gut, which in turn causes you to be less able to absorb nutrients and regulate blood sugar (insulin resistance) and store fat effectively.

2. Stomach disturbances and food intolerance's, with symptoms including abdominal pain, bloating, gas, constipation, and diarrhoea. Food intolerance's like lactose or gluten may be related to poor quality gut bacteria. If your gut health is good, you will have less difficulty processing food and eliminating waste, leading to no symptoms.

3. Feeling fatigued or having disturbed sleep – some research indicates a link between poor gut health and interrupted sleep patterns, causing fatigue. There seems to be a correlation between mental health, metabolic function, and inflammation.

4. Autoimmune conditions – an unhealthy gut may lead to lower immunity and poorer immune system, leading to the development of inflammation and autoimmune diseases. In these cases, the body starts to attack itself rather than the invader.

5. Skin irritations – for example, psoriasis may be related to gut bacteria, with an imbalance in gut bacteria impacting the immune system.

Which foods to limit or avoid?

- Fatty foods are high in saturated fat, which is hard for the body to digest and are a problem for people with inflammatory bowel disease, as well as being one of the factors contributing to heart disease

- Regularly drinking alcohol damages, the gut lining and therefore the microbiome – it should be one of the first things to try cutting out

- Eating a lot of red and processed meat is shown to be inflammatory, particularly in the colon

- Artificial sweeteners contain sugar alcohols, which for some can cause bloating, gas, and stomach pain (look out on labels for ingredients ending in ‘ols’, e.g., sorbitol

- Sugar is one of the most harmful foods we consume, and it directly decreases the amount and diversity of healthy gut bacteria, which can lead to increased inflammation in the body.

- Highly processed foods, such as pre-made, and ready meals are connected to a rise in irritable bowel disease because for them to be preserved and taste good they contain artificial sweeteners, preservatives, emulsifiers, thickeners, and flavourings which are harmful to the gut health. It is worth noting that some convenience foods are nutritious, such as canned vegetables, canned fish and frozen fruit and vegetables.

- Dairy can be inflammatory for some people because it can cause symptoms such as lactose intolerance. Some milk sources contain harmful hormones and antibiotics, which while sometimes needed antibiotics can also cause damage to gut health and healthy gut bacteria.

It is important to note, that none of these foods would be harmful if eaten in moderation and in conjunction with a healthy balanced diet. Risk increases with the frequency of consumption.

Foods that promote gut health and immunity

As said, our gut and digestive health are directly impacted by the food we consume, so we can adapt our diet to promote a healthy and diverse gut microflora.

1. Increase/optimises fibre intake - legumes, like black beans and chickpeas, whole grains, like oats and quinoa, leafy greens like kale, spinach, chard, and vegetables, like broccoli, Brussels sprouts, cauliflower, cabbage, radishes and asparagus, nuts, like almonds and pistachios, fruits, like apples, bananas, and plums (which contain soluble fibre, pectin which improves insulin resistance and lower cholesterol), sunflower seeds which also contain vitamin E and selenium

2. Eat probiotics — foods such as fermented yoghurt, kefir, sauerkraut, pickles, and kimchi

3. Eat prebiotics — a type of non-digestible fibre (which ‘feed’ the probiotics), e.g., garlic, Jerusalem artichokes, onions, chickpeas, and oats

4. Drink green tea (anti-inflammatory/oxidant)

5. Ensure daily omega-3 fatty acids (anti-inflammatory): fish oils, flaxseed oil, walnuts, and chia seeds. Wild salmon and sardines have been linked to cardiovascular health, and mood regulation and help fight inflammation.

6. Deal with stress – this is essential because chronic stress suppresses the immune system

7. Stop smoking – we know this negatively impacts the body and cigarettes also contain high levels of sugar. Smoking can aggravate stomach ulcers and inflammatory conditions of the bowel, and it is also an important risk factor for stomach cancer

8. Increase vitamin E sources (sunflower seeds, almonds, peanuts, spinach) and beta-carotene (antioxidant) through yellow, red, and green (leafy) vegetables, such as spinach, carrots, sweet potatoes, and red peppers

9. Ensure daily zinc intake which enhances immunity by promoting the development of immune cells. Sources are pumpkin seeds, nuts, chickpeas, mushrooms, spinach

10. Vitamin C — modulates immunity e.g., guava, blackcurrants, red and green peppers, kiwi, oranges, broccoli, and vitamin D from daily sunlight

11. Include beta-glucan sources, which are said to stimulate the immune system by increasing chemicals that prevent infections. Sources are oats, barley, medicinal mushrooms e.g., reishi and shiitake

12. Herbal remedies such as echinacea, elderberry and ginseng promote immunity

13. Exercise (promotes immunity)

14. Address sleep habits (7–9 hours)

15. No / minimum alcohol, no refined sugars, high-fat foods, and dairy

Why is increasing fibre vital for gut health?

Fibre is a complex carbohydrate. Its role in health generally is often overlooked yet it is one of the easiest and cheapest ways to address gut and digestive health and is part of a healthy balanced diet.

According to government guidelines, adults are recommended to get around 30g of dietary fibre each day for general health benefits. Unfortunately, the latest statistics show that the average intake for adults is just over half of the RDA, at 18g daily.

Fibre is in two forms – soluble (dissolves in water) e.g., legumes, oats, barley, fruit and insoluble (does not dissolve in water), e.g., wheat, vegetables, and seeds.

Fibre helps to regulate bowel movements, and most high-fibre foods are low in calories, sugar, and fat so they are healthy sources and will also help you to feel fuller for longer, which helps avoid overeating.

Eating daily fibre has also been shown to reduce the risk of colon cancer, diverticulitis, and diverticulosis.

It plays a role as a source of nutrition for bacterial culture, which makes up the mucosal lining, which may help to protect against IBS, colitis, and Crohn’s disease.


What we choose to consume and put in our bodies has a direct impact on digestive and gut health, and health outcomes. A healthy digestive system and gut should be able to digest foods, absorb nutrients and excrete body waste effectively.

70% of our immune system resides in the gut or digestive system. Our GIT contains nerve cells, known as ‘the brain of the gut’ which are part of the nervous system. When we are under consistent and chronic stress, our body goes into ‘fight or flight’ mode, and this affects the digestive system and gut health. Therefore, managing stress levels can positively impact gut health, and avoid bloating and stomach disorders.

Regarding diet, there are things we should limit or avoid, to ensure a healthy gut, which includes fatty foods, alcohol, artificial sweeteners, excessive red meat, sugar, highly processed foods, and dairy.

Conversely, there are foods we can optimize and increase to promote healthy gut bacteria and a healthy digestive system. One of the most important is daily fibre intake, where the RDA is 30g/daily for adults. We get fibre from many sources, which should be included as part of a healthy balanced diet.

Taking steps to prioritize gut and digestive health, through diet and lifestyle change has been shown to have a positive impact on reducing the risk of many health conditions.



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