Oligofructose (OF) is a fructose- based oligosaccharide and defined in the European Union as a dietary fibre. Enzymatically derived from the longer chain inulin in chicory, it is commonly used in processed food to improve mouth feel in fat-free products. OF is poorly digested and absorbed in the small bowel so passes to the colon where it is fermented by the bacteria usually resident in the colon, termed the microbiota. This process produces gases such as hydrogen and sometimes methane, and short-chain fatty acids (SCFAs) which have a variety of roles including nutrition to colonocytes, immunological effects and modulation of intestinal motility. Its presence in the colon alters the composition of the microbiota, with reported potential benefits to health, leading to its description as a 'prebiotic'.