The gut is much more than where our food gets digested, it's also home to millions of tiny bacteria that help to keep us healthy.
Foods high in dietary fibre support gut health but most of us don't consume enough of them, says Australian research dietitian Megan Rebuli.
She tells Kathryn Ryan why fibre - especially resistant starches - are the focus of the new CSIRO Gut Care Guide.
Check out these new CSIRO recipes - Green Seed Bowl and Lush Yoghurt Bowls
Bloating, reflux and changes in bowel habits (especially constipation) could be signs you're not getting enough fibre.
Eating 25 to 30 grams of high-fibre foods every day encourages good bacteria in our gut to grow, Dr Rebuli says.
There are 3 main types of dietary fibre - soluble fibres (that dissolve in water), insoluble fibre (aka roughage) and resistant starches.
Resistant starches - found in greenish bananas, legumes, whole grains and garlic - are especially beneficial for gut health, she says, as they provide food for the 'good bacteria' that live in the lining of our large intestine and bowel.
Watch a CSIRO video about resistant starches:
The best thing you can do for your gut is to eat a variety of fibre-rich foods, Dr Rebuli says.
Choose whole grains, pasta, brown rice, chickpeas and yoghurt over highly processed food and fast food.
While it's hard to overeat fibre, it can be done if you're having fibre as a supplement and not enough water on the side, she says.
If you haven't been eating much fibre, introduce it to your diet slowly.
Gut-friendly recipes from the RNZ collection:
Prebiotic and Probiotic Kumara Leek Soup
Five-minute Feijoa and Coconut Sponge Cake