Authored by Assoc. Prof. Teresa Mitchell-Paterson from Bourke Street Clinic
In my practice I assist many patients with gastrointestinal symptoms that are made worse by the introduction of higher fibre in the diet. It is a myth that high fibre diets suit everyone, sometimes the key to a successful resolution of upset bowel conditions is quite the reverse. A low-fibre diet is recommended for individuals with certain gastrointestinal (GI) diseases, particularly those affecting the large bowel, such as Crohn’s disease, post bowel cancer surgery and stoma care, ulcerative colitis, diverticulitis, and irritable bowel syndrome (IBS). Fibre, while generally beneficial for digestion, can exacerbate symptoms like bloating, diarrhea, and abdominal pain in people with inflamed or sensitive gastrointestinal tracts. In some cases, particularly after surgery or during disease flare-ups or the disease, reducing fibre intake can help minimise mechanical irritation and allow the gut to heal. However, a low-fibre diet can pose challenges for gut microbiome health and metabolic control, necessitating strategies to maintain overall digestive and metabolic well-being.
One key approach to making a low-fibre diet healthier is the inclusion of resistant starch. Unlike regular fibre, resistant starch is not completely broken down in the small intestine; instead, it reaches the colon, where it serves as a fermentable substrate for beneficial gut bacteria. This fermentation process produces short-chain fatty acids (SCFAs), particularly butyrate, which helps maintain the integrity of the gut lining, reduce inflammation, and support overall digestive health. Resistant starch is also beneficial for blood sugar regulation because it slows glucose absorption, reducing postprandial spikes and improving insulin sensitivity. This makes it particularly useful for individuals managing diabetes alongside GI conditions that require fibre restriction.
Sources of resistant starch suitable for a low-fibre diet include cooked and cooled potatoes, white rice, green bananas, green banana flour and certain legumes that have been well-cooked and dehulled. These foods provide the metabolic benefits of fibre without contributing to the bulk and irritation that insoluble fibre can cause. The cooling process enhances the resistant starch content by allowing starch molecules to recrystallise into a form that resists digestion in the small intestine, maximising its prebiotic potential.
While a low-fibre diet restricts many fruits and vegetables, careful selection of low-fibre options ensures adequate vitamin and mineral intake without exacerbating GI symptoms. Well-tolerated low-fibre fruits include bananas, peeled peaches, peeled apples, applesauce, and melon varieties, which provide essential nutrients while minimising gut irritation. These fruits contain simple sugars and pectin, a soluble fibre that is gentler on the digestive system than insoluble fibre. Vegetables that are peeled, cooked, or strained, such as zucchini, carrots, potatoes (without skins), green beans, baby spinach and pumpkin, can also be included. Cooking breaks down plant cell walls, reducing fibre content and making these foods easier to digest. Straining vegetable soups and purees can further minimise fibre while preserving their nutrient content.
A low-fibre diet does not have to mean poor gut health, nor does it need to be boring. By incorporating resistant starch and carefully selecting low-fibre fruits and vegetables, individuals can maintain a balanced gut microbiome, support metabolic health, and reduce inflammation without aggravating their digestive conditions. Pairing these strategies with adequate protein, healthy fats, and hydration ensures that a restricted-fibre diet remains nutritionally sufficient, interesting and beneficial for long-term health.
NB: Always consult an accredited natural medicine practitioner when looking to change your food intake and support your gut health.
Find a practitioner in your area here: https://www.atms.com.au/find-a-practitioner/
