Gut health briefing
Resistant starch
Resistant starch is a specific type of fibre that resists digestion in the small intestine. In the large intestine it ferments and feeds your gut bacteria, which produce short-chain fatty acids. The result can be a healthier gut and a range of broader health benefits.
How resistant starch works
Unlike most starches, resistant starch passes through the small intestine without being broken down. It reaches the large intestine intact, where your gut bacteria ferment it.
It resists digestion
Resistant starch is not absorbed in the small intestine, so it arrives in the large intestine still intact.
It feeds your gut bacteria
In the large intestine the resistant starch ferments, providing fuel for the bacteria living there.
It produces short-chain fatty acids
As the bacteria ferment it, they produce short-chain fatty acids, which are linked with various health benefits and better gut health.
Consuming resistant starch rich foods may promote a healthy gut microbiome and help support digestive and gastrointestinal health.
Foods high in resistant starch
A great way to increase your resistant starch intake is through a diet rich in legumes, whole grains, and cooked and cooled starchy foods. The table below ranks foods from the very best sources down to moderate ones. Serving sizes are half a cup unless otherwise stated.
| Ranking | Fruit and vegetables | Legumes (half cup) | Grains (half cup) |
|---|---|---|---|
| Very best | Semi-ripe banana, 1 large Green banana flour, 1 tbsp |
||
| Best | Potato, cooked, chilled and then reheated | Baked beans, canned Kidney beans, canned Fava beans, canned Butter beans, canned |
Rice, white, ready to heat Wholegrain barley groats, cooked |
| High | Potato, cooked then chilled Ripe banana, 1 large Peas, cooked |
Chickpeas, canned Lentils, dehulled green or red, chilled Lentils, dehulled green or red, chilled and reheated |
Rice, white, long grain, cooked then chilled |
| Moderate | Potato, cooked Peas, canned Sweet corn, cooked |
Kidney beans, cooked Mixed beans, canned Pinto refried bean, canned Lentils, dehulled green or red, cooked |
Muesli Corn cereal, flakes Rice, white, long grain, cooked |
Tips for building it into your diet
Easy swaps to add resistant starch
- Add semi-ripe bananas to your smoothies, or choose green banana flour to make pancakes.
- Serve your main meals with a side of white rice.
- Upgrade your salads by adding cooked and cooled potato, canned chickpeas or fava beans, or cooked barley groats.
Increasing fibre intake safely
- Gradually increase fibre intake to allow the digestive system to adjust.
- Stay well hydrated, as consuming more fibre without sufficient water may cause gastrointestinal blockage.
- Expect some mild symptoms such as gas and bloating as a sign your gut microbiome is adjusting to the increased fibre intake. This is not necessarily a sign of intolerance.
- If you get gut symptoms, slightly reduce your fibre intake for a few days before slowly increasing as tolerated.
Recipe ideas
Potato and bean salad (serves 6)
Ingredients
- 1kg chat potatoes, skin on, washed, halved
- 400g butter beans or mixed beans, canned, drained
- 3/4 cup Greek yoghurt
- 1 tablespoon wholegrain mustard
- 1/2 tablespoon Dijon mustard
- 1 small red onion, thinly sliced
- 2 tablespoons dill, roughly chopped
- 3 stalks celery, chopped
- 1 cup peas, cooked (or frozen peas, thawed)
- 2 spring onions, thinly sliced
- Salt and pepper for seasoning
Method
- Bring a large pot of water to the boil. Add potatoes and cook until tender, approximately 15 minutes, then drain. Set aside to cool in a large salad bowl.
- In a small bowl combine Greek yoghurt, wholegrain mustard, Dijon mustard and dill. Stir well to combine.
- Add beans, peas, red onion, celery, spring onion and dressing to the potatoes and stir gently to combine.
- Refrigerate for at least an hour before serving.
- Season with salt and pepper to taste.
Green banana flour pancakes (serves 2)
Ingredients
- 1 cup green banana flour
- 2 tsp baking powder
- 1 tbsp honey (adjust for sweetness)
- 1/2 tsp cinnamon, ground
- 1/4 tsp salt
- 2 large eggs
- 1 tsp vanilla extract
- 1/2 cup milk (dairy or non-dairy)
- 1 to 2 tbsp oil, for cooking
- Optional: honey, fruit, ricotta cheese, nuts for topping
Method
- In a bowl, whisk together green banana flour, baking powder, cinnamon and salt.
- Add eggs, vanilla extract, honey, and milk.
- Mix well until a runny consistency.
- Heat a pan over medium heat, and add 1 to 2 tbsp of oil to the pan.
- Once the pan is hot, add batter onto the surface, and cook for 1 to 2 minutes then flip for the same period.
- Add optional toppings, for example fresh berries, ricotta cheese, pecans and a drizzle of honey.
Frequently asked questions
What is resistant starch and why is it good for you?
Resistant starch is a type of fibre that resists digestion in the small intestine and instead reaches the large intestine, where gut bacteria ferment it. That fermentation produces short-chain fatty acids, which are linked with several health benefits and better gut health. In effect, resistant starch acts as food for beneficial gut bacteria, supporting the microbiome much like other prebiotic fibres.
What foods are high in resistant starch?
Top sources include semi-ripe bananas, and starchy foods that have been cooked and then cooled, such as potatoes cooked, chilled and reheated. Canned beans like baked, kidney, fava and butter beans are good sources, as are cooked-and-cooled white rice and wholegrain barley. A practical strategy is to build meals around legumes, whole grains and starchy foods that have been cooked and then cooled, since cooling raises the resistant starch content.
Does cooling potatoes and rice increase resistant starch?
Yes. Cooking and then cooling starchy foods like potatoes and rice increases their resistant starch content, which is why cooked-and-cooled or reheated versions feature among the better sources. This is a simple way to get more resistant starch from everyday foods. As with other fibres, it is best to increase intake gradually and stay well hydrated, since mild gas or bloating usually just signals the gut microbiome adjusting.
Reviewed by Rohan Smith, BHSc Nutritional Medicine · Elemental Health & Nutrition, Adelaide. Last reviewed 13 June 2026.
Important: This summary is general information, not personalised medical advice, diagnosis, or a treatment protocol. Speak with a qualified practitioner about your individual situation. Book a consultation →