Despite growing awareness of healthy eating, most Australians still fall short on dietary fibre. Research using Australia's National Nutrition and Physical Activity Survey found that fewer than three in ten adults meet the recommended adequate intake for fibre, and more than eight in ten fall short of the higher target that reduces chronic disease risk. Fibre plays a fundamental role in digestive health, heart health and blood sugar regulation, and while most people associate it simply with preventing constipation, its benefits extend well beyond regular bowel movements.
The gut contains trillions of microorganisms that help digest food, regulate immune function and produce compounds that support overall health. Dietary fibre nourishes many of these beneficial bacteria, allowing them to thrive and produce short-chain fatty acids that help maintain the intestinal barrier and support healthy inflammatory responses. As understanding of the gut microbiome grows, fibre is increasingly recognised as one of the most important nutrients for long-term wellbeing.
As a Clinical Nutritionist and Certified Healthy Gut Practitioner, Jolie Kerwin helps clients understand how everyday food choices influence digestive health, energy levels and chronic disease risk. Rather than promoting restrictive diets or quick fixes, she focuses on practical, evidence based nutrition strategies that fit into real life.
What is Dietary Fibre?
Dietary fibre refers to the parts of plant foods that are not fully digested or absorbed in the small intestine. Unlike carbohydrates broken down for energy, fibre passes through much of the digestive tract intact, performing a range of important functions along the way. It occurs naturally in vegetables, fruits, legumes, whole grains, nuts and seeds.
The Australian Dietary Guidelines recommend adults consume between 25 and 30 grams of fibre each day, depending on age and sex, yet most Australians consume considerably less.
There are two main types of fibre, and both contribute to good health. Soluble fibre dissolves in water to form a gel-like substance, and may help support healthy cholesterol levels, regulate blood glucose, slow digestion and feed beneficial gut bacteria. Good sources include oats, barley, legumes, apples, pears and chia seeds. Insoluble fibre adds bulk to stool and supports regular bowel movements, and is commonly found in whole grains, wheat bran, nuts, seeds, cauliflower and green beans. Most plant foods contain a combination of both.
Why Fibre Matters So Much For Gut Health
One of fibre's most significant roles is supporting the gut microbiome. The trillions of bacteria living in the digestive tract rely on dietary fibre as a food source, and when these beneficial bacteria ferment fibre, they produce compounds called short-chain fatty acids. Research suggests these compounds help nourish the cells lining the colon, maintain the gut barrier, support immune regulation and contribute to healthy inflammatory responses. Without adequate fibre, beneficial bacteria may decline while less desirable bacteria become more dominant, which is why maintaining a diverse microbiome through regular fibre intake is increasingly recognised as an important strategy for long-term digestive health.
Fibre's best known benefit is supporting bowel regularity. Adequate intake helps soften stools, improve consistency and reduce constipation. It's worth noting that increasing fibre too quickly can temporarily increase bloating or gas, which is why dietitians usually recommend building intake up gradually while drinking plenty of water.
Fibre Does More Than Support Digestion
Although fibre is often associated with gut health, its benefits extend throughout the body. Research has linked higher fibre intake with improved cardiovascular health, metabolic health, weight management and blood sugar regulation. The Heart Foundation encourages Australians to eat more wholegrain and whole plant foods as part of an overall heart healthy eating pattern, noting that the fibre in wholegrains can help lower and regulate cholesterol.
Soluble fibre in particular may help lower LDL, or "bad", cholesterol by binding to it in the digestive tract before it's absorbed, and higher fibre intake has consistently been associated with lower rates of cardiovascular disease in population studies. Because soluble fibre also slows digestion, it may help reduce rapid blood glucose spikes after meals, making fibre rich foods an important part of dietary patterns for people managing or reducing their risk of type 2 diabetes.
Fibre rich foods generally require more chewing and digest more slowly, which many people find helps them feel fuller for longer after meals. That said, fibre shouldn't be viewed as a weight loss supplement in its own right. It contributes to a broader dietary pattern that supports long-term wellbeing rather than acting as a shortcut on its own.
Signs You May Not Be Eating Enough Fibre
Most people don't notice they're low in fibre until digestive symptoms appear, and because fibre influences so many systems in the body, inadequate intake may contribute to a range of symptoms, though these can also have other causes. Common signs include constipation or irregular bowel movements, bloating, feeling hungry soon after meals, difficulty maintaining healthy cholesterol levels, blood sugar fluctuations and reduced dietary variety.
Constipation isn't the only warning sign to watch for. Insufficient fibre can also affect gut microbiome diversity, digestive comfort, cholesterol management, blood glucose control and long-term cardiovascular health, which is why Accredited Practising Dietitians tend to look at overall dietary quality rather than focusing on a single symptom in isolation. If symptoms persist, it's worth seeking professional advice rather than simply adding a fibre supplement without understanding the underlying cause.
The Best Foods For Increasing Fibre Naturally
The good news is that fibre shows up in plenty of everyday foods, and most people can increase their intake through small, sustainable changes rather than supplements.
- Vegetables: broccoli, carrots, pumpkin, sweet potato, Brussels sprouts, spinach, kale
- Fruits: apples, pears, berries, oranges, kiwi fruit, avocados
- Legumes: chickpeas, lentils, kidney beans, black beans, split peas, among the richest natural sources of fibre and a good source of plant protein too
- Whole grains: oats, brown rice, quinoa, wholemeal bread, wholegrain pasta, barley
- Nuts and seeds: almonds, walnuts, pistachios, chia seeds, flaxseeds, pumpkin seeds, which also bring healthy fats and key micronutrients
Common Myths About Fibre
Despite being one of the best studied nutrients, fibre attracts its share of misconceptions. More fibre isn't always better; increasing intake too quickly can temporarily worsen bloating, gas or discomfort, especially for people with IBS or sensitive digestion, so gradual, sustainable increases work best. Fibre supplements can be useful in certain situations, but they don't provide the full range of vitamins, minerals, antioxidants and phytochemicals found naturally in whole plant foods, so food should remain the primary source wherever possible. And carbohydrates aren't the enemy fibre is often mistaken for one; whole grains, legumes, fruit and vegetables are nutrient rich carbohydrate foods that support overall health, and restricting them unnecessarily can actually reduce fibre intake and gut microbiome diversity.
How To Increase Fibre Without Upsetting Your Gut
Many people experience bloating simply because they increase fibre too rapidly, so a gradual approach tends to work best. Swapping refined breakfast cereals for rolled oats, natural muesli or high fibre wholegrain cereals is an easy starting point. Aiming to include vegetables at both lunch and dinner, even just one extra serve a day, can make a meaningful difference over time, as can gradually replacing white bread, white rice and refined pasta with wholemeal and wholegrain alternatives where appropriate. Snacking on fresh fruit, nuts, roasted chickpeas, yoghurt with berries or vegetable sticks with hummus instead of highly processed snacks is another simple shift. As fibre intake increases, fluid needs increase too, so staying well hydrated helps fibre move comfortably through the digestive system.
Personalised Nutrition Makes The Difference
There's no single "perfect" diet for everyone. Some people tolerate high fibre foods extremely well, while others living with IBS, inflammatory bowel disease, coeliac disease, food intolerances or SIBO may need more carefully tailored nutrition strategies. Rather than following advice from social media or restrictive online diets, working with an Accredited Practising Dietitian allows nutrition advice to be individualised according to symptoms, medical history and personal goals.
How Jolie Kerwin Helps Clients Improve Gut Health
As a Clinical Nutritionist and Certified Healthy Gut Practitioner, Jolie Kerwin believes nutrition should be practical, enjoyable and sustainable. Rather than encouraging restrictive eating, she works collaboratively with each client to understand their lifestyle, health concerns and individual goals before developing personalised nutrition strategies grounded in current evidence. She has a particular interest in digestive health, women's health and preventative nutrition, helping clients improve their relationship with food while supporting long-term gut health and overall wellbeing. Whether someone is managing IBS, digestive discomfort, food intolerances or simply wants to improve their dietary habits, Jolie focuses on realistic changes that can be maintained for life rather than short-term fixes.
Frequently Asked Questions (FAQS)
1. How much fibre should adults eat each day?
The Australian Dietary Guidelines recommend women consume approximately 25 grams of fibre per day and men approximately 30 grams, though individual requirements vary by age and life stage. Most Australians fall well short of these targets.
2. Can eating more fibre improve gut health?
Yes. Fibre feeds beneficial gut bacteria, helping them produce short-chain fatty acids that support gut barrier function and healthy immune responses. A diverse, fibre rich diet is one of the most effective ways to support a healthy gut microbiome.
3. Why does fibre sometimes cause bloating?
When fibre intake increases too quickly, gut bacteria ferment the extra fibre more rapidly, temporarily producing more gas. Increasing fibre gradually while drinking plenty of water usually helps the digestive system adapt.
4. Are fibre supplements as good as food?
Supplements can be appropriate in certain situations, but they don't provide the full range of vitamins, minerals, antioxidants and plant compounds found naturally in whole foods. Food should remain the primary source of fibre wherever possible.
5. Should people with IBS eat more fibre?
Some forms of fibre are better tolerated than others. People with IBS often benefit from individualised advice from a Dietitian or Nutritionist, who can recommend the type and amount of fibre best suited to their symptoms.
If you've been dealing with bloating, irregular digestion, or just want to build a more gut-friendly way of eating without diving into restrictive diets or fads, it may be worth getting some personalised guidance rather than guessing. Jolie Kerwin is a Clinical Nutritionist and Certified Healthy Gut Practitioner with a particular interest in digestive health, women's health and preventative nutrition. More detail on her approach is available on her Health Hunter profile.
References
- Reynolds A et al. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet, 2019. https://www.thelancet.com/article/S0140-6736(18)31809-9/fulltext
- National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand. https://www.nhmrc.gov.au/about-us/publications/nutrient-reference-values-australia-and-new-zealand-including-recommended-dietary-intakes
