Prebiotic dietary fibre is a double-edged sword for people with intestinal disorders. While fibre has been shown to alleviate constipation, certain high fibre foods, may increase gas production and bloating that may induce symptoms in people with Irritable Bowel Syndrome (IBS). However, a study by Monash University has found that supplementing a specific fibre, sugarcane fibre, alongside a low FODMAP diet has been shown to be effective in providing improvement in both IBS type symptoms and stool satisfaction in patients with IBS.

IBS is the most prevalent functional gastrointestinal (GI) disorder, affecting 15% of the global population. The exact pathophysiology of IBS is still poorly understood as it varies from person to person and often has multiple contributing dynamics. Some of the factors that predispose individuals to IBS include genetics, dietary components, stress-related nervous and endocrine systems, and alternations in the gut microbiome. In people with these predispositions, food sensitivities and dysbiosis of the gut microbiome are among the triggers that can provoke symptoms.

The most common symptoms of IBS include constipation, diarrhea (alternating between the two), abdominal pain, bloating and gas. Patients with IBS can be classified into four major subtypes depending on the predominant stool pattern, including IBS with constipation (IBS-C), IBS with diarrhea (IBS-D), IBS with mixed bowel habits (IBS-M) and unclassified IBS (link).

Food plays a role in symptom induction in many people, but the foods that trigger IBS symptoms will vary for each person. A low FODMAP diet – a diet low in fermentable

oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) has been proven effective in reducing IBS-related symptoms. But a diet low in FODMAPs restricts common sources of dietary fibre, subsequently starving the gut of valuable prebiotics benefits and microbiome support. Moreover, reduction in fibre intake can also have a negative impact on other aspects of gut health, especially bowel regularity and constipation.

Prebiotic dietary fibre for IBS may sound a bit like an oxymoron because many types of prebiotic fibres are high FODMAP fermentable fibres that can create havoc on the digestive system due to rapid gas production and symptom induction. Many common types of prebiotic fibres are poorly tolerated by individuals with IBS and hence many IBS sufferers will avoid prebiotics as part of a temporary low FODMAP diet.

From the functional point of view, two of the most important attributes of prebiotic dietary fibre include

  • Bulking – to help normalise regular bowel movements, regulate transit time, increase stool output, and normalise stool form.
  • Fermentation in the gut – to support gut microbiome that in turn can offer array of health benefits that stretches even beyond gut.

So how can people with IBS overcome the fibre gap without the risk of inducing GI symptoms? Well, the answer lies in the use of prebiotic dietary fibres with slow and uniform fermentation rates in the gut.

  • Fibres that ferment more quickly (e.g. oligosaccharides in FODMAPs) may exacerbate symptoms via sudden gas production. In contrast, fibres that resist fermentation (cellulose) or slowly ferment (e.g. psyllium) are less likely to induce symptoms via accumulation of gas.
  • Fibres capable of enhancing stool bulk through particulate stimulation of the mucosa and retention of water may assist with increasing stool mass while normalizing stool consistency and colonic transit.
  • Rapidly fermented fibres may not be suitable for this purpose because bulking effects tend to diminish upon fermentation, while subsequent increases in gas volume may induce symptoms in the presence of visceral hypersensitivity.

Researchers in the Department of Gastroenterology at Monash University have shown how strategic use of specific types of dietary fibres based on their fermentation functionality in the gut can help in IBS patients in their recent study (link).

What kind of dietary fibres did the study test?

The study used sugarcane fibre – that is minimally fermented and has bulking properties. This means that it produces minimal gas and may offer laxative effects. The study also utilised resistant starch (RS) known to ferment more slowly than other prebiotics like inulin.

Who were the participants and how was the study conducted?

In this double-blind crossover trial 26 patients with IBS were randomly assigned to 1 of 3 low FODMAP diets differing only in total fibre content:

  • control – 23 g/day
  • sugarcane fibre – 33 g/day
  • fibre combination (sugarcane fibre with resistant starch) – 45 g/day

Each diet lasted 14 days with most food provided and separated by washout period of ≥ 21 days during which participants resumed habitual dietary habits, evaluated by direct questioning by a dietitian.

What did the study find?

  • Overall, across all participants, the three dietary interventions led to improved GI symptoms (abdominal pain, bloating, gas) compared with before they took part in the study.

– This confirmed the efficacy of low FODMAP diet in improving the IBS-related GI symptoms. Also, more importantly, the concomitant fibre supplementation with low FODMAP diet as reported did not diminish the therapeutic effects of reducing FODMAP intake.

  • The study found that supplementing sugarcane fibre with and without resistant starch with a low FODMAP diet was well tolerated by these patients and improved bowel habits by increasing stool output and normalising low stool water content.

– The study also noted that there were signals that the fibre combination (sugarcane fibre + resistant starch) tended to be less well tolerated compared with Sugarcane fibre only. The effects experienced however were small and did not lead to participant withdrawal. This may likely be due to higher fermentability of RS than sugarcane fibre thus, likely tendency to increase bloating and passage of gas with resistant starch supplementation.

  • Stool output was noted to be 50% higher during the fibre-supplemented (both Sugarcane only & Sugarcane + resistant starch) vs control diets.

– It is interesting to note that despite the increase in overall total fibre intake by the participants on co-supplementation with resistant starch, the stool output was identical with that of sugarcane fibre only supplementation. This suggest that resistant starch may offer minimal bulking effect (also reported previously – link).

So, in conclusion, this study clearly confirmed the benefits experienced in IBS patients (although in small numbers) from inclusion of specific dietary fibres like sugarcane fibre during low FODMAP diet thus supporting the application to overcome the fibre gap.

What can you do with this information?

The Low FODMAP diet is well-recognised to improve IBS- related symptoms however, it can also starve the gut by reducing the abundance of prebiotic fibre needed for GI healing. However, it’s quite evident that not all prebiotics support bowel regularity or are well-tolerated by those with IBS due to their rapid fermentability in the gut.

If this new research has captured your interest in sugarcane for general gut health, there is only one source of “Virgin Sugarcane Prebiotic” in the world.

Health Food Symmetry harvests and produces Virgin Sugarcane Prebiotic in Queensland, Australia.

  • Kfibre is Monash University Low FODMAP certified, is gluten free, high in prebiotic fibre with 95% sucrose reduced. Plus, in addition to the fibres with prebiotic benefits, Kfibre Virgin sugarcane is a complex fibre retaining other phytonutrients present in sugarcane plant. So, you can enjoy the excellent benefits of prebiotics & phytonutrients from sugarcane without the sugar.

Contrary to many prebiotic fibres, Kfibre – Virgin Sugarcane prebiotic is fermented at a slow and uniform fermentation rate (link) in the entire colon (large intestine), influencing the beneficial gut microbiota and delivering SCFAs including butyrate to especially nourish the hindgut (link). This makes it not only well tolerated by those with IBS, but beneficial to the maintenance of intestinal health as well.

You too can enjoy the gut joy so many others have already found when they tried

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By Dr Tanvi Shinde, PhD & Contributions by Joanna Baker (APD | RN)