How to Eat More Fibre Every Day and Feed Your Gut Microbiome
Updated: 3 hours ago
Most of us eat well below the fibre we need. Adults in the UK are advised to aim for about 30g a day, yet the average intake is closer to 18g. The good news is that closing the gap is easier than it sounds, and your gut bacteria will thank you for it.
In this guide you will find simple ways to increase fibre intake across the day, a sample menu and a few habits that help keep your microbiome rich and varied.
Why fibre matters for your gut microbiome
Your large intestine is home to trillions of bacteria, known together as your gut microbiome. Fibre is their main food. Your body cannot digest most of it, so it travels to the colon, where bacteria ferment it.
This fermentation produces short-chain fatty acids such as butyrate, which help nourish the cells lining your gut. Research also links a fibre-rich, plant-rich diet with a more diverse microbiome, and diversity is generally seen as a good sign.
Fibre also supports regular bowel movements, helps you feel full after meals and is linked with better long-term heart and metabolic health.
Two kinds of fibre, and why you want both
You will often hear about soluble and insoluble fibre. Most plant foods contain a mix of the two.
Soluble fibre dissolves in water and forms a gel. You find it in oats, beans, lentils, apples, citrus fruit and flaxseed.
Insoluble fibre adds bulk and helps food move through. You find it in wholegrains, nuts, seeds and the skins of fruit and vegetables.
You do not need to count each type. Eating a wide range of plants covers both.
Aim for variety, not only grams
Total grams matter, but variety matters just as much. Different bacteria prefer different fibres, so a varied diet feeds a wider range of them.
A large study of gut bacteria found that people who ate 30 or more different plant foods a week had a more diverse microbiome than those who ate 10 or fewer. Plants count in every form: vegetables, fruit, wholegrains, beans, lentils, nuts, seeds, herbs and spices.
A simple habit is to keep a running tally on the fridge. Every new plant of the week gets a tick. You will be surprised how quickly herbs, spices and a handful of seeds add up.
10 practical ways to increase fibre intake today
Start with a fibre-rich breakfast. Porridge made with rolled oats, topped with berries and a spoonful of ground flaxseed or chia seeds, gives you fibre before nine o'clock.
Swap refined for wholegrain. Choose wholemeal bread, wholewheat pasta and brown rice. Mixing half white and half wholegrain is a gentle start if the full switch feels like a big jump.
Add pulses to meals you already make. Stir lentils into bolognese, chickpeas into a curry or beans into a soup. A tin of pulses is cheap, quick and one of the best fibre sources there is.
Keep the skin on. Potatoes, apples, pears and carrots have much of their fibre in the skin. Scrub them well rather than peeling.
Fill half your plate with vegetables. Aim for different colours across the week. Leafy greens, broccoli, peas, carrots and peppers all contribute.
Snack on fruit, nuts and seeds. A pear, a handful of almonds or a small bowl of raspberries beats most packaged snacks for fibre.
Choose whole fruit over juice. Juicing removes most of the fibre. A whole orange gives you far more than a glass of orange juice.
Sprinkle seeds on almost anything. Chia, flaxseed, pumpkin and sunflower seeds go well on yoghurt, salads, soups and porridge.
Cook and cool starchy foods. When potatoes, rice or pasta are cooked and then cooled, some of their starch becomes resistant starch, which your gut bacteria enjoy. Potato salad and cold rice or pasta salads are easy ways to use this.
Add herbs, spices and a few prebiotic foods. Onions, garlic, leeks, asparagus, oats and slightly underripe bananas all contain fibres that feed beneficial bacteria.
A sample day: around 30g of fibre or more
Fibre values vary by brand and portion, so treat these figures as rough guides.
Breakfast: porridge made with 40g rolled oats, a handful of raspberries and a tablespoon of chia seeds. Roughly 11 to 12g.
Lunch: lentil and vegetable soup with two slices of wholemeal bread. Roughly 12 to 14g.
Snack: one pear with the skin on and a few almonds. Roughly 6g.
Dinner: chickpea and vegetable curry with brown rice, plus a side of broccoli. Roughly 10 to 12g.
Together that comes to somewhere around 35g, depending on your portions. If it looks like a lot, remember you do not need to change everything at once.
How to increase fibre without the bloating
Raising fibre too quickly is the most common reason people feel gassy, bloated or uncomfortable and give up. Your microbiome needs time to adjust.
Go slowly. Add one or two new fibre-rich foods each week rather than overhauling everything overnight.
Drink enough fluid. Fibre absorbs water, so aim for plenty of water or other unsweetened drinks through the day.
Rinse tinned pulses. This washes away some of the compounds that can cause wind.
Chew well and eat steadily. Digestion starts in the mouth.
Keep moving. A short walk after meals can help digestion.
Some mild extra wind in the first week or two is normal. If you have persistent pain, bloating or changes in your bowel habits, speak to your doctor.
Keeping your microbiome rich in the long term
Fibre is the foundation, but a few other habits help.
Eat fermented foods. Live yoghurt, kefir, sauerkraut, kimchi and miso can add helpful live bacteria to your diet. Choose unpasteurised or "live" versions where possible.
Rotate your foods. Try one new vegetable, grain or pulse each week so your gut meets new fibres.
Include colourful plants. Berries, dark leafy greens, olive oil, herbs and spices provide plant compounds called polyphenols, which gut bacteria also use.
Limit ultra-processed foods. They are usually low in fibre and are often high in additives, sugar and refined starch.
Look after sleep, stress and movement. These also influence the gut, even though they are not on your plate.
When fibre is not straightforward
For most people, more fibre is a good thing. But it is not a one-size-fits-all rule.
If you have irritable bowel syndrome, inflammatory bowel disease, diverticular disease or have had bowel surgery, the right type and amount of fibre can be different for you. Some people also find certain foods, such as wheat, onions or dairy, trigger symptoms even when they eat plenty of fibre.
If fibre-rich foods regularly leave you uncomfortable, personalised guidance can save months of trial and error. A food intolerance test can be one useful piece of the picture when you are working out which foods suit you.
Key takeaways
Most adults need about 30g of fibre a day and many eat much less.
Variety matters: aim for 30 different plant foods a week.
Build up gradually and drink enough fluid.
Use easy swaps: wholegrains, pulses, skins on, seeds on everything.
If you have a digestive condition, get personalised advice before making big changes.
Want help building a fibre-rich plan that suits you?
Every gut is different. If you would like a personalised plan that fits your health, your tastes and your routine, you can book an initial consultation.
The information in this post is general and is not a substitute for medical advice. If you have a medical condition, please speak to your doctor before changing your diet.
Cecilia Neri Linares, BSc Food Science & Nutrition, MSc Nutrition Education (Columbia University)
Nutrition Educator, E-nutritionist, London
Reviewed: October 2026
© 2026 Cecilia Neri Linares | E-Nutritionist. All rights reserved.
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