Rome Foundation Working Group

Am J Gastroenterol 2013; 108:707–717; doi:10.1038/ajg.2013.96; published online 16 April 2013

Short-Chain Carbohydrates and Functional Gastrointestinal Disorders

Susan J Shepherd BAppSci, MND, PhD1, Miranda C E Lomer RD, PhD2 and Peter R Gibson MD, FRACP3

  1. 1Department of Dietetics and Human Nutrition, La Trobe University, Bundoora, Victoria, Australia
  2. 2Nutritional Sciences Division, King's College London, London, UK
  3. 3Department of Gastroenterology, The Alfred Hospital and Monash University, Melbourne, Victoria, Australia

Correspondence: Susan J. Shepherd, Department of Dietetics and Human Nutrition, La Trobe University, Cnr Kingsbury and Lower Plenty Road, Bundoora, Victoria 3086, Australia. E-mail: s.shepherd@latrobe.edu.au or sue@shepherdworks.com.au

Received 17 December 2012; Accepted 5 March 2013
Advance online publication 16 April 2013

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Abstract

Carbohydrates occur across a range of foods regularly consumed including grains such as wheat and rye, vegetables, fruits, and legumes. Short-chain carbohydrates with chains of up to 10 sugars vary in their digestibility and subsequent absorption. Those that are poorly absorbed exert osmotic effects in the intestinal lumen increasing its water volume, and are rapidly fermented by bacteria with consequent gas production. These two effects alone may underlie most of the induction of gastrointestinal symptoms after they are ingested in moderate amounts via luminal distension in patients with visceral hypersensitivity. This has been the basis of the use of lactose-free diets in those with lactose malabsorption and of fructose-reduced diets for fructose malabsorption. However, application of such dietary approaches in patients with functional bowel disorders has been restricted to observational studies with uncertain efficacy. As all dietary poorly absorbed short-chain carbohydrates have similar and additive effects in the intestine, a concept has been developed to regard them collectively as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) and to evaluate a dietary approach that restricts them all. In patients with irritable bowel syndrome, there is now an accumulating body of evidence, based on observational and comparative studies, and on randomized-controlled trials that supports the notion that FODMAPs trigger gastrointestinal symptoms in patients with functional bowel disorders, and that a diet low in FODMAPs offers considerable symptom relief in the majority of patients who use it.