FODMAPs or fermentable oligosaccharides, disaccharides, monosaccharides, and polyols are short-chain carbohydrates that are poorly absorbed in the small intestine and ferment in the colon. They include short-chain oligosaccharide polymers of fructose (fructans) and galactooligosaccharides (GOS, stachyose, raffinose), disaccharides (lactose), monosaccharides (fructose), and sugar alcohols (polyols), such as sorbitol, mannitol, xylitol, and maltitol. Most FODMAPs are naturally present in food and the human diet, but the polyols may be added artificially in commercially prepared foods and beverages.
FODMAPs may cause digestive discomfort in some people. The reasons are hypersensitivity to luminal distension and/or a proclivity to excess water retention and gas production and accumulation, but they do not cause intestinal inflammation. Naturally occurring FODMAPs may help avert digestive discomfort for some people because they produce beneficial alterations in the gut flora. They are not the cause of these disorders, but a low-FODMAP diet, restricting FODMAPs, might help to improve digestive symptoms in adults with irritable bowel syndrome (IBS) and other functional gastrointestinal disorders (FGID). Avoiding all FODMAPs long-term may have a detrimental impact on the gut microbiota and metabolome.
FODMAPs, especially fructans, are present in small amounts in gluten-containing grains and have been identified as a possible cause of symptoms in people with non-celiac gluten sensitivity. They are only minor sources of FODMAPs when eaten in the usual standard quantities in the daily diet. As of 2019, reviews conclude that although FODMAPs present in wheat and related grains may play a role in non-celiac gluten sensitivity, they only explain certain gastrointestinal symptoms, such as bloating, but not the extra-digestive symptoms that people with non-celiac gluten sensitivity may develop, such as neurological disorders, fibromyalgia, psychological disturbances, and dermatitis. Consuming a low FODMAP diet without a previous medical evaluation could cause health risks because it can ameliorate and mask digestive symptoms of celiac disease, delaying or avoiding its correct diagnosis and therapy.