FODMAPs (Fermentable Oligo-, Di-, and Mono-saccharides,And Polyols) are short-chain carbohydrates that are:
- Osmotically active, so they, after ingesting, drag water from the intestinal vessels into the intestinal lumen, thus causing diarrhea
- Fermentable (degradable by intestinal bacteria yielding large amount of gases, like hydrogen or carbon dioxide, thus causing abdominal bloating
- Fructans - chains of fructose with one glucose molecule on the end. Only minimal amounts of fructans may be absorbed in human intestine. They may interfere with absorption of fructose, thus aggravating symptoms in fructose malabsorption. Fructans-rich foods are: wheat (white bread, pasta, pastries, cookies), onions, andartichokes; other not commonly problematic foods with fructans are asparagus, leeks, garlic, chicory roots and chicory based coffee substitutes. Fructans with over 10 molecules of fructose in a chain are known as inulins and those with less than 10 fructoses are referred as fructo-oligosaccharide (FOS) or oligofructose. Fructans cause problems mainly in fructose malabsorption.
- Galactans (like stacchyose and raffinose) are chains of galactose molecules with one fructose molecule on the end. They act much like fructans. Main galactans-rich foods are legumes (soy, beans, chickpeas, lentils), cabbage and brussel sprouts.
- Lactose (milk sugar). Lactose is in dairy products, but it may be also found inchocolate and other sweets, beer, pre-prepared soups and sauces, and so on. Lactose is poorly absorbed in lactose intolerance, SIBO and in small intestinal inflammation (Crohn’s disease, celiac disease).
- Fructose (fruit sugar). Fructose-rich foods are honey, dried fruits like prunes, figs, dates, or raisins, apples, pears, sweet cherries, peaches, agave syrup, watermelon, papaya. Fructose is often added to commercial foods and drinks as high fructose corn syrup (HFCS). Fructose causes symptoms even in healthy people, if ingested in excess, especially in fructose malabsorption, but also in SIBO.
- Polyols, also known as sugar alcohols (appearing as artificial sweeteners in commercial foods and drinks):
- Sorbitol may appear in “sugar-free chewing gum”, “low calorie foods”; naturally it appears in stone fruits: peaches, apricots, plums).
- Xylitol naturally appears in some berries. A pack of chewing gum containing sorbitol or xylitol may cause bloating or diarrhea in a healthy child and especially in persons with fructose malabsorption or SIBO.
- Other polyols, like mannitol, isomalt, erithrytol, arabitol, erythritol, glycol, glycerol, lactitol, ribitol, may be problematic in fructose malabsorption and SIBO.