Reviewed by Barbara Yassa, Accredited Practising Dietitian

While gut health may not be the most glamorous of subjects, it’s certainly a topical one. And no wonder, when we’re still discovering the huge impact gut health has on us both physically and mentally – from digestive issues and chronic diseases to our moods and immunity. To make it easier to make healthy choices for you and your family, here are some gut health basics worth knowing about.

The lowdown on gut health

When we talk about the gut, what do we mean exactly?

The gut is your gastrointestinal system, which includes your stomach, small intestine and colon. And when you think about it, your gut is truly amazing. Its inner surface area is around 32 sqm and it has more nerve cells than the human brain (which is why it’s often referred to as the second brain)! So it’s something you want to take care of.

Your gut does a lot more than just process food into the nutrients your body needs to function, it also plays a key role in your overall health and wellbeing [1]. Here are just some of things gut health (or lack of it) is linked to:

• Digestive issues – From the uncomfortable to the debilitating, it’s no surprise an unhealthy gut can bring on a range of symptoms including bloating, cramps, abdominal pain, constipation and diarrhoea.
• Intestinal diseases – Gut health is also linked to irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and even diverticulitis [2] (an inflammation or infection due to bacteria trapped inside one of the small pouches formed in the wall of the colon).
• Immunity – The state of your gut affects the way your body responds to infection and fights disease. An unbalanced gut microbiome can change the immune system and may increase susceptibility to autoimmune diseases [3].
• Chronic diseases – While more research needs to be done, it’s thought that many chronic diseases begin in the gut due to the effects of long-term inflammation. On the positive side, a healthy gut may boost heart health, brain health and even prevent some cancers [4].
• Obesity and weight problems – Researchers are investigating the link between gut health and obesity, and how the balance of bacteria in the gut affects how appetite is regulated [5].
• Mental wellness – Our understanding of how our gut health and what we eat may affect our moods and wellbeing is still growing, but many experts believe that gut imbalance may increase things like anxiety, depression and even chronic pain [6].

They’re called good bacteria for a reason

The magical workings of your gut are due to its microbiome (a mini ecosystem), which is a diverse community of organisms – or microbes – including bacteria, fungi and viruses. It’s hard to believe, but there are around 40 trillion bacterial cells in your gut (so you’re actually more bacteria than human!).

While we often think of bacteria as the bad guys, it’s important to remember there are good and bad bacteria. The good bacteria play a crucial role when it comes to your health and wellbeing including your digestion, immune system, weight, ability to fight disease and even your moods.

More than just helping your body digest food, the good bacteria work to keep the bad bacteria from getting out of control and making you sick. In short, they keep you healthy by supporting your immune function, controlling inflammation, nourishing your gut lining, and helping your body absorb nutrients and medications.

Prebiotics vs. probiotics (and why you need them both)

Without getting too technical, a healthy gut needs a balance of both prebiotics and probiotics. The good news is, you don’t need to take any supplements unless your diet is inadequate or you have a specific need – which is where a health professional can advise you. But you can definitely help things along by eating probiotic and prebiotic-rich food.

Put simply, probiotics are live microorganisms that are intended to have health benefits when consumed or applied to the body [7] and help to boost the good bacteria in your gut. Foods containing probiotics include some yoghurts and fermented food such as sauerkraut, kombucha and pickled vegetables.

Slightly less talked about (but just as important) are prebiotics. These feed the good bacteria in your gut (a bit like fertiliser!), and come from certain carbs that humans can’t digest. So the good guys can’t work as well without them. Some of the best sources of prebiotics include:

• Oats
• Bananas
• Berries
• Lentils, chickpeas, beans and peas
• Asparagus
• Onions
• Garlic

Fibre – your gut’s BFF

Related to increasing prebiotics and probiotics to keep your gut healthy and happy, is upping your intake of dietary fibre. That’s because fibre is made up of the indigestible parts of plant foods which are fermented by the good bacteria that live in the large intestine.

Eating more fibre-rich foods like whole grains, veggies, fruit, legumes, nuts and seeds not only keeps your digestive system healthy, but can also help you to:

• Lose weight
• Regulate your blood sugar levels
• Reduce constipation
• Improve your heart health
• Reduce your risk of some cancers [8]

With the latest research highlighting how important it is to eat a diverse variety of fibre, here are three types of fibre you should aim to include more of in your diet. It really is a case of the more, the merrier!

Insoluble fibre – Doesn’t dissolve in water and adds bulk to the contents of the gastrointestinal tract, which helps to keep your bowel movements regular. It’s found in:

• Unpeeled fruit and veg
• Whole grain bread and cereal
• Nuts and seeds (like flax and chia seeds)

Soluble fibre – Dissolves in water and forms a thick gel in your stomach that slows down the passage of food through your gastrointestinal tract. This may help stabilise blood glucose levels in people with diabetes, lower LDL cholesterol levels (that’s the “bad” one) and slow down digestion to help you feel fuller for longer. Good sources include:

• Fruit and veg
• Nuts and seeds (like flax and chia seeds)
• Oats
• Barley
• Psyllium husk

Resistant starch – Unlike other starch, resistant starch isn’t digested until it gets into the large intestine. It’s then broken down by good bacteria in a way that helps keep the lining of the bowel healthy. There’s lots of resistant starch in:

• Beans and legumes (white beans, lentils, chickpeas, and red kidney beans)
• Underripe bananas
• Cooked and cooled potato, rice or pasta

Other things that may affect gut health

While fuelling your body with a diverse range of whole foods is good for your gut (and the rest of you!), your diet isn’t the only thing to affect your gut health. Other lifestyle and environmental factors that can have an impact [9] (not all of them obvious), include:

• Alcohol – Studies show that drinking too much alcohol can cause an imbalance in gut microflora (called "dysbiosis").
• Smoking – While it’s not the first thing that springs to mind, it’s no surprise that smoking is bad for your gut health. Tobacco smoke contains more than 1,000 chemicals, such as nicotine and free radicals, and is associated with increased levels of inflammatory markers which have detrimental effects on the gut. The good news is that stopping smoking increases your gut flora diversity.
• Exercise – Being active is good for – well – just about everything, and that includes your gut health. Regular exercise can change the composition of your gut microbiome which can promote the growth of beneficial gut bacteria (that means anything from going to the gym and team sports to walking and gardening!).
• Sleep – While we don’t want to give you one more reason to toss and turn, not getting enough quality sleep may be harmful to your gut bacteria. So, make it a priority to hit the sack early! If you need them, here are a few handy sleep tips.
• Stress – We all know stress can affect us physically and mentally, and it’s also thought that high stress levels can alter gut bacteria. While more research needs to be done, reducing the stress and anxiety in our life can only be a good thing!
• Antibiotics – The relationship between antibiotics and gut health is complex. Antibiotics work by eliminating all bacteria (they don’t differentiate between good or bad gut bacteria), so they can lead to changes in the composition and diversity of the gut flora. Antibiotics should only be used as advised by your doctor.

In short, your gut is your body’s quiet achiever, and should be treated with the respect it deserves. This not only means eating a diverse range of food rich in probiotics, prebiotics and fibre, but nurturing your health and wellbeing by putting those good lifestyle habits in place! As always, if you have any questions or concerns, chat to your healthcare professional.

For help with healthy eating, you can put your Top Extras cover towards consultations with a dietitian near you. And if you have a health condition, our Healthcare Services team offers a range of programs including nutrition plans and dietitian support to eligible members with Hospital cover.

References:
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3983973/
2. Diverticulosis and diverticulitis - Better Health Channel
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3448089/
4. https://www.healthline.com/nutrition/gut-microbiome-and-health#TOC_TITLE_HDR_9
5. https://www.webmd.com/digestive-disorders/ss/slideshow-how-gut-health-affects-whole-body
6. https://foodandmoodcentre.com.au/
7. Probiotics: What You Need To Know (nih.gov)
8. https://dietitianconnection.com/news/clinical/benefits_of_fibre/
9. https://www.healthline.com/nutrition/8-things-that-harm-gut-bacteria#TOC_TITLE_HDR_5
10. https://www.health.harvard.edu/vitamins-and-supplements/health-benefits-of-taking-probiotics