SummaryRead the full fact sheet
- The bacteria and other micro-organisms in your gut are known as your gut microbiome. The bacteria help to break down food, turning it into nutrients your body can use.
- Your gut microbiome impacts both your physical and mental health.
- Many factors, including the foods you eat, can impact the type and balance of bacteria found in your gut.
What is gut health and gut microbiome?
Your gut is your gastrointestinal system and includes your stomach, intestines and colon. It digests and absorbs nutrients from food and excretes waste.
There is no clear definition of gut health, and it can mean something different for researchers, medical professionals and the community. Throughout this page, we refer to gut health as having a healthy gut microbiome and limited digestive symptoms.
About 200 different species of bacteria, viruses and fungi live in your large intestine. The bacteria and other micro-organisms in your gut are known as your gut microbiome. The bacteria help to break down food, turning it into nutrients your body can use.
Certain types of bacteria in your gut may contribute to some diseases. Some microorganisms are harmful to our health, but many are beneficial and necessary for a healthy body.
We are learning that the variety of bacteria in your gut is an important indicator of the health of your microbiome.
The health of your gut can impact both your physical and mental health.
Many factors, including the foods you eat, can impact the type of bacteria found in your digestive tract. What we eat can have short-term and long-term effects on our gut microbiome environment.
Why gut health is important
The gut breaks down the foods you eat and absorbs nutrients that support your body’s functions.
The importance of the gut to our overall health is a topic of increasing research in the medical community. Research is showing us that our gut microbiome can affect every organ in our body.
It is understood that there are links between gut health and:
- endocrine disorders – such as
- gastrointestinal disorders – such as and inflammatory bowel disease
A higher level of diversity in gut bacteria is an important indicator of the health of your microbiome.
While research is ongoing, it appears that your gut health plays an important role in your overall health.
Signs of an unhealthy gut
Your gut microbiome can be affected by:
- too little sleep
- lack of physical activity
- eating too many ultra-processed foods
- and drinking
- taking antibiotics.
- digestive symptoms – such as , bloating, , and
- sleep disturbances or
- mood/emotional state – such as high stress, or
- high frequency of infectious illnesses – such as the .
How to improve your gut health
You may be able to improve your gut health through lifestyle and diet changes.
Dietary fibre in foods can improve your gut health as it can help keep us regular, reduce the risk of and feed the healthy bacteria in our gut.
Wholefoods, such as fruits, vegetables, legumes, wholegrains and nuts,
may prevent the growth of some bacteria linked to diseases and inflammation.
Gut health and diet
Your gut bacteria are influenced by what you eat. It is important to give them the right fuel to have a balanced gut microbiome.
The best way to maintain a healthy microbiome is to eat a range of fresh, wholefoods, mainly from plant sources like fruits, vegetables, legumes, beans, nuts and wholegrains.
Eat a high fibre diet
is important for our gut health for many reasons. Fibre can affect the function of our gut, for example, the digestion and absorption of nutrients, how quickly or slowly things move through and the quality of our stools.
The breakdown of fibre by our gut bacteria can also create important products which can influence the development of gastrointestinal conditions such as bowel cancer.
Fibre has other benefits to our health apart from the gut, for example, reducing our risk of developing heart disease and type 2 diabetes.
Fibre is only found in foods that come from a plant. Australian adult women should be aiming to eat at least 25g of fibre a day, and men 30g.
Foods that are high in fibre include:
Prebiotic fibres, which are not found in all high fibre foods, may be especially helpful for our gut microbiome, as they can act as a fertiliser for the healthy bacteria in our gut.
They are found in some types of:
- vegetables – for example leek, onion and garlic
- legumes – for example chickpeas, beans and lentils
- wholegrains – for example rye bread, barley and oats
- nuts – for example pistachios, cashews and almonds.
Eat a diverse range of food
The diversity of food on your plate can help lead to a more diverse microbiome, which is an indicator of a healthy gut microbiome.
Aim to eat at least 30 different types of plant-based foods a week.
Limit ultra-processed foods
Eat foods that are as close to their natural state as possible to support your gut health.
While almost all foods have had some kind of , it is best to eat foods that are minimally processed. These foods retain their nutritional value and do not usually have added , , unhealthy or such as emulsifiers and artificial sweeteners, all of which may impact your gut health.
Unprocessed foods include fruits, vegetables, wholegrains, unflavoured , eggs, seafood, . Ultra-processed foods include deli meats such as ham and salami, many breakfast cereals, ready-made meals, sweet desserts and many packaged snacks such as chips.
Water assists with the breakdown of food, so that your body can absorb nutrients. Water also assists with softening stools, helping prevent constipation.
Drinking plenty of water may also be linked to increased diversity of bacteria in the gut.
Eat foods rich in polyphenols
Polyphenols are plant compounds that may beneficially impact our gut microbiome.
Foods rich in polyphenols include:
- and spices
- colourful fruits and vegetables
- nuts and seeds
- green and black tea
- cocoa and dark chocolate.
Chewing your food thoroughly and eating slowly may reduce digestive discomfort such as gas, pain and bloating.
Eat fermented foods
Fermented foods include:
While research into fermented foods is limited, the bacteria found in some fermented foods have been linked with digestive health and other benefits.
Gut health and breastfeeding
Gut health and exercise
Exercise can also positively affect the gut microbiome.
Gut health and stress
What you eat, your gut health and your mental health are all linked.
Gut health and sleep
Gut health and probiotic supplements
There are many nutrients in wholefoods that cannot be packaged into a single supplement. Nutrients in foods also interact with each other in a helpful way and this cannot be replicated in a pill.
Many people are interested in taking probiotic supplements. If you’re in good health, it is generally not necessary to take a probiotic for your gut health.
In some cases, there is research to support taking a probiotic, however just like medications, you need to take a specific probiotic for the health condition you are trying to manage.
Before taking probiotics or any other supplement, it’s a good idea to speak to an accredited practising dietitian and your general practitioner to see if it’s safe and which one might work.
Gut health and antibiotics
While antibiotics can be very important and useful, they can also have a negative impact on your gut microbiome.
Antibiotics aim to kill the harmful bacteria when you have an infection or illness, but in doing so they can remove some of the beneficial bacteria in your gut.
Myths about gut health
There are no miracle cures for good gut health.
There’s no scientific evidence that individual foods or any other product will rapidly heal an unbalanced gut microbiome.
There’s also no scientific evidence that colon cleansing improves health or is beneficial at all.
Research into gut health is relatively new and understanding of this complex topic is developing. Be careful of non-evidence-based information about gut health. Focusing on eating healthily with the tips suggested on this page is the best evidence we have so far.