FODMAPs are small carbohydrate (sugar) molecules which are poorly absorbed in the small intestine, osmotically active molecules (draw water into the large intestine) and rapidly fermented by bacteria, producing carbon dioxide, hydrogen, and methane gas.
FODMAP is an acronym for Fermentable – Oligosaccharides – Disaccharides –, Monosaccharides – And – Polyols.
Fermentable:
Fermentable carbohydrates are sugars that are broken down and digested by bacteria in our intestines, producing gas and other by-products.
Oligosaccharides:
Oligosaccharides are short chains of carbohydrate molecules linked together. • Fructans (a chain of fructose molecules) and galacto-oligosaccharides (a chain of galactose molecules) are oligosaccharides that humans cannot break down and properly absorb in the small intestine.
Disaccharides:
Disaccharides are two carbohydrate molecules linked together. • Lactose, the sugar found in milk and dairy products, is a disaccharide composed of glucose and galactose. Lactose must be broken down by the digestive enzyme lactase before it can be absorbed in the small intestine. In people with lactose intolerance, the level of lactase enzyme is insufficient to properly digest lactose and lactose travels to the colon where fermentation occurs.
Monosaccharides:
Monosaccharides are single carbohydrate molecules. • Fructose, the sugar found in many fruits and some vegetables, is a monosaccharide and does not require any digestion before it is absorbed. When foods containing equal amounts of fructose and glucose are eaten, glucose helps fructose to be completely absorbed.However, when fructose is present in greater quantities than glucose, fructose absorption depends upon the activity of sugar transporters located in the intestinal wall. The ability to absorb excess fructose varies from person to person. In people with fructose malabsorption, the capacity of sugar transporters is limited and excess fructose travels to the colon where fermentation occurs.
Polyols:
Polyols, or sugar alcohols, are a type of carbohydrate that humans can only partially digest and absorb in the small intestine. • Polyols, such as sorbitol, mannitol, xylitol, maltitol and isomalt, mimic the sweetness of sucrose (table sugar), however, because their absorption is much slower, only a small amount of what is eaten is actually absorbed. Polyols are often used as low-calorie sweeteners in sugar-free and diet products.
Where FODMAPs are found
FODMAPs are found in foods naturally or as additives and include fructose (in fruits and vegetables), fructans (like fructose, found in some vegetables and grains), lactose (dairy), galactans (legumes), and polyols (artificial sweeteners).
These foods are not necessarily unhealthy products. Some of them contain healthy prebiotics that help stimulate the growth of beneficial gut bacteria, but in certain people, eating or drinking them causes gastrointestinal symptoms.
Click HERE to learn more about which foods are high in FODMAPs.
Resources:
Canadian Digestive Health Foundation - What are FODMAPs