Fructose: role in the formation of intestinal symptoms

Abstract

Fructose is a simple sugar that is present in fruit and honey, but is also a major component in the two most commonly used sweeteners, sucrose (table sugar), and high fructose corn syrup (HFCS). Intake of fructose has increased markedly over the last several hundred years, and currently the intake of added sugars approaches 15 percent of overall energy intake in the average western diet. The prevalence of fructose malabsorption is relatively high in healthy adults (~34%) and is even greater in patients with functional gastrointestinal disorders. Symptoms following fructose ingestion, or fructose intolerance, are common in patients with irritable bowel syndrome (IBS). Due to the paucity of targeted therapy for IBS, many patients turn to dietary modifications for symptom management. In recent years the low-FODMAPs diet for treatment of IBS has gained increasing popularity. The acronym FODMAP stands for “fermentable oligosaccharides, disaccharides, monosaccharides, and polyol” and includes foods with fructose in excess of glucose, oligosaccharides including fructans, galacto-oligosaccharide and sugar polyols such as sorbitol and mannitol and lactose. The composition of FODMAPs diets and their mechanisms of action in IBS have been intensively studied in the past decade, but since this link is not specific to fructose. Dietary FODMAP might exacerbate intestinal symptoms by increasing small intestinal water volume, colonic gas production, and intestinal motility. Dietary FODMAPs restriction is associated with reduced fermentation and significant symptom improvement in some IBS patients.