FODMAPs or fermentable oligosaccharides, disaccharides, monosaccharides, and polyols[1] are short chain carbohydrates that are poorly absorbed in the small intestine and are prone to absorb water 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.[1][2] 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. In fact, naturally occurring FODMAPs may help avert digestive discomfort for some people because they produce beneficial alterations in the gut flora.[3][4][5][6] They are not the cause of these disorders,[7] 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).[7][8][9][10][11] Avoiding all FODMAPs long-term may have a detrimental impact on the gut microbiota and metabolome.[2][9][11][12]

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.[13][14][15][16][3] They are only minor sources of FODMAPs when eaten in the usual standard quantities in the daily diet.[13] 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.[3][17][13] The use of 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.[18]


Some FODMAPs, such as fructose, are readily absorbed in the small intestine of humans via GLUT receptors.[19] Absorption thus depends on the appropriate expression and delivery of these receptors in the intestinal enterocyte to both the apical surface, contacting the lumen of the intestine (e.g. GLUT5), and to the basal membrane, contacting the blood (e.g. GLUT2).[20] Improper absorption of these FODMAPS in the small intestine leaves them available for absorption by gut flora. The resultant metabolism by the gut flora leads to production of gas and potentially results in bloating and flatulence.[7]

Nevertheless, although FODMAPs can cause certain digestive discomfort in some people, not only do they not cause intestinal inflammation, but they help to prevent it because they produce beneficial alterations in the intestinal flora that contribute to maintain the good health of the colon.[4][5][6]

FODMAPs are not the cause of irritable bowel syndrome nor other functional gastrointestinal disorders, but rather a person develops symptoms when the underlying bowel response is exaggerated or abnormal.[7]

Fructose malabsorption and lactose intolerance may produce IBS symptoms through the same mechanism but, unlike with other FODMAPs, poor absorption of fructose is found in only a minority. Lactose intolerance is found in a majority of adults with the exception of certain geographic populations, notably those of European descent.[21] Many who benefit from a low FODMAP diet need not restrict fructose or lactose. It is possible to identify these two conditions with hydrogen and methane breath testing and thus eliminate the necessity for dietary compliance if possible.[7]

Sources in the dietEdit

The significance of sources of FODMAPs varies through differences in dietary groups such as geography, ethnicity, and other factors.[7] Commonly used FODMAPs comprise the following:[22]

  • oligosaccharides, including fructans and galacto-oligosaccharides
  • disaccharides, including lactose
  • monosaccharides, including fructose
  • polyols, including sorbitol, xylitol, and mannitol

Fructans, galactans, and polyolsEdit

Sources of fructansEdit

Sources of fructans include wheat, rye, barley, onion, garlic, Jerusalem and globe artichoke, beetroot, dandelion leaves, the white part of leeks, the white part of spring onion, brussels sprouts, savoy cabbage, and prebiotics such as fructooligosaccharides (FOS), oligofructose and inulin.[7][23][24] Asparagus, fennel, red cabbage and radicchio contain moderate amounts but may be eaten if the advised portion size is observed.[24]

Sources of galactansEdit

Pulses and beans are the main dietary sources (although green beans, canned lentils, sprouted mung beans, tofu (not silken), and tempeh contain comparatively low amounts).[24][23] Supplements of the enzyme supplement alpha-galactosidase may reduce symptoms [25] if brands containing other FODMAPs, such as polyol artificial sweeteners, are avoided.[citation needed]

Sources of polyolsEdit

Polyols are found naturally in some fruit (particularly stone fruits), including apples, apricots, avocados, blackberries, cherries, lychees, nectarines, peaches, pears, plums, prunes, watermelon, and in some vegetables, including cauliflower, mushrooms, snow peas and mange-tout peas. Cabbage, chicory, and fennel contain moderate amounts, but may be eaten in a low-FODMAP diet if the advised portion size is observed.[24]

Polyols used artificially as bulk sweeteners added to commercially prepared food and beverages include isomalt, maltitol, mannitol, sorbitol and xylitol.[7][23] As noted above, they exacerbate the effect of galactans when consumed.

Fructose and lactoseEdit

People following a low-FODMAP diet may be able to tolerate moderate amounts of fructose and lactose, particularly if they have lactase persistence.[26][27][citation needed]

Sources of fructoseEdit

Sources of lactoseEdit

Low-FODMAP dietEdit

A low-FODMAP diet consists in the global restriction of all fermentable carbohydrates (FODMAPs),[7] that is recommended only for a short time. A low-FODMAP diet is recommended for managing patients with irritable bowel syndrome (IBS) and can reduce digestive symptoms of IBS including bloating and flatulence.[28]

A low-FODMAP improves digestive symptoms in adults with irritable bowel syndrome in several studies,[8][9][10][11] but its long-term use can have negative effects because it causes a detrimental impact on the gut microbiota and metabolome.[2][9][11][12] It should only be used for short periods of time and under the advice of a specialist.[29] More studies are needed to evaluate its effectiveness in children with irritable bowel syndrome.[8] There is only a little evidence of its effectiveness in treating functional symptoms in inflammatory bowel disease from small studies that are susceptible to bias.[30][31] More studies are needed to assess the true impact of this diet on health.[9][11]

Role in non-celiac gluten sensitivityEdit

FODMAPs that are present in gluten-containing grains have been identified as a possible cause of gastrointestinal symptoms in people with non-celiac gluten sensitivity, in place of,[32] or in addition to, gluten and other proteins in gluten-containing cereals, named amylasetrypsin inhibitors (ATIs).[14][13] The amount of fructans in these cereals is small. In rye they account for 3.6%–6.6% of dry matter, 0.7%–2.9% in wheat, and barley contains only trace amounts.[3] They are only minor sources of FODMAPs when eaten in the usual standard amounts in the daily diet.[13] Wheat and rye may comprise a major source of fructans when consumed in large amounts.[7]

In a 2018 double-blind, crossover research study on 59 persons on a gluten-free diet with challenges of gluten, fructans or placebo, intestinal symptoms (specifically bloating) were borderline significantly higher after challenge with fructans, in comparison with gluten proteins (P=0.049).[3][17] Although the differences between the three interventions was very small, the authors concluded that fructans are more likely to be the cause of gastrointestinal symptoms of non-celiac gluten sensitivity, rather than gluten.[3] In addition, fructans used in the study were extracted from chicory root, so it remains to be seen whether the wheat fructans produce the same effect.[17]

A 2018 review concluded that although fructan intolerance may play a role in non-celiac gluten sensitivity, it only explains some gastrointestinal symptoms, but not the extra-digestive symptoms that people with non-celiac gluten sensitivity may develop, such as neurological disorders, fibromyalgia, psychological disturbances, and dermatitis; and that FODMAPs cause digestive symptoms when the person is hypersensitive to luminal distension.[3]

A 2019 review concluded that wheat fructans can cause certain IBS-like symptoms, such as bloating, but they are not likely to cause immune activation nor extra-digestive symptoms since, in fact, many people with non-celiac gluten sensitivity report resolution of their symptoms after removing gluten-containing cereals while they continue to eat fruits and vegetables with high FODMAPs content in their diet.[17]

See alsoEdit


  1. ^ a b Gibson PR, Shepherd SJ (June 2005). "Personal view: food for thought--western lifestyle and susceptibility to Crohn's disease. The FODMAP hypothesis". Alimentary Pharmacology & Therapeutics. 21 (12): 1399–409. doi:10.1111/j.1365-2036.2005.02506.x. PMID 15948806. S2CID 20023732.
  2. ^ a b c Tuck CJ, Muir JG, Barrett JS, Gibson PR (September 2014). "Fermentable oligosaccharides, disaccharides, monosaccharides and polyols: role in irritable bowel syndrome". Expert Review of Gastroenterology & Hepatology. 8 (7): 819–34. doi:10.1586/17474124.2014.917956. PMID 24830318. S2CID 28811344.
  3. ^ a b c d e f g Verbeke, K (February 2018). "Nonceliac Gluten Sensitivity: What Is the Culprit?". Gastroenterology. 154 (3): 471–473. doi:10.1053/j.gastro.2018.01.013. PMID 29337156. Although intolerance to fructans and other FODMAPs may contribute to NCGS, they may only explain gastrointestinal symptoms and not the extraintestinal symptoms observed in NCGS patients, such as neurologic dysfunction, psychological disturbances, fibromyalgia, and skin rash.15 Therefore, it is unlikely that they are the sole cause of NCGS.
  4. ^ a b Makharia A, Catassi C, Makharia GK (December 2015). "The Overlap between Irritable Bowel Syndrome and Non-Celiac Gluten Sensitivity: A Clinical Dilemma". Nutrients (Review). 7 (12): 10417–26. doi:10.3390/nu7125541. PMC 4690093. PMID 26690475.
  5. ^ a b Greer JB, O'Keefe SJ (2011). "Microbial induction of immunity, inflammation, and cancer". Frontiers in Physiology (Review). 1: 168. doi:10.3389/fphys.2010.00168. PMC 3059938. PMID 21423403.
  6. ^ a b Andoh A, Tsujikawa T, Fujiyama Y (2003). "Role of dietary fiber and short-chain fatty acids in the colon". Current Pharmaceutical Design (Review). 9 (4): 347–58. doi:10.2174/1381612033391973. PMID 12570825.
  7. ^ a b c d e f g h i j Gibson PR, Shepherd SJ (February 2010). "Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach". Journal of Gastroenterology and Hepatology. 25 (2): 252–8. doi:10.1111/j.1440-1746.2009.06149.x. PMID 20136989. S2CID 20666740. Wheat is a major source of fructans in the diet. (...) Table 1 Food sources of FODMAPs. (...) Oligosaccharides (fructans and/or galactans). Cereals: wheat & rye when eaten in large amounts (e.g. bread, pasta, couscous, crackers, biscuits)
  8. ^ a b c Turco R, Salvatore S, Miele E, Romano C, Marseglia GL, Staiano A (May 2018). "Does a low FODMAPs diet reduce symptoms of functional abdominal pain disorders? A systematic review in adult and paediatric population, on behalf of Italian Society of Pediatrics". Italian Journal of Pediatrics (Systematic Review). 44 (1): 53. doi:10.1186/s13052-018-0495-8. PMC 5952847. PMID 29764491.
  9. ^ a b c d e Staudacher HM, Irving PM, Lomer MC, Whelan K (April 2014). "Mechanisms and efficacy of dietary FODMAP restriction in IBS". Nature Reviews. Gastroenterology & Hepatology (Review). 11 (4): 256–66. doi:10.1038/nrgastro.2013.259. PMID 24445613. S2CID 23001679. An emerging body of research now demonstrates the efficacy of fermentable carbohydrate restriction in IBS. [...] However, further work is urgently needed both to confirm clinical efficacy of fermentable carbohydrate restriction in a variety of clinical subgroups and to fully characterize the effect on the gut microbiota and the colonic environ¬ment. Whether the effect on luminal bifidobacteria is clinically relevant, preventable, or long lasting, needs to be investigated. The influence on nutrient intake, dietary diversity that might also affect the gut microbiota, and quality of life also requires further exploration as does the possible economic effects due to reduced physician contact and need for medication. Although further work is required to confirm its place in IBS and functional bowel disorder clinical pathways, fermentable carbohydrate restriction is an important consideration for future national and international IBS guidelines.
  10. ^ a b Marsh A, Eslick EM, Eslick GD (April 2016). "Does a diet low in FODMAPs reduce symptoms associated with functional gastrointestinal disorders? A comprehensive systematic review and meta-analysis". European Journal of Nutrition. 55 (3): 897–906. doi:10.1007/s00394-015-0922-1. PMID 25982757. S2CID 206969839.
  11. ^ a b c d e Rao SS, Yu S, Fedewa A (June 2015). "Systematic review: dietary fibre and FODMAP-restricted diet in the management of constipation and irritable bowel syndrome". Alimentary Pharmacology & Therapeutics. 41 (12): 1256–70. doi:10.1111/apt.13167. PMID 25903636. S2CID 27558785.
  12. ^ a b Heiman ML, Greenway FL (May 2016). "A healthy gastrointestinal microbiome is dependent on dietary diversity". Molecular Metabolism (Review). 5 (5): 317–320. doi:10.1016/j.molmet.2016.02.005. PMC 4837298. PMID 27110483.
  13. ^ a b c d e Fasano A, Sapone A, Zevallos V, Schuppan D (May 2015). "Nonceliac gluten sensitivity". Gastroenterology (Review). 148 (6): 1195–204. doi:10.1053/j.gastro.2014.12.049. PMID 25583468. Cereals such as wheat and rye, when consumed in normal quantities, are only minor sources of FODMAPs in the daily diet. (...) Table 1. Sources of FODMAPs (...) Oligosaccharides (fructans and/or galactans). Cereals: wheat and rye when eaten in large amounts (eg, bread, pasta, couscous, crackers, biscuits)
  14. ^ a b Volta U, Caio G, Tovoli F, De Giorgio R (2013). "Non-celiac gluten sensitivity: questions still to be answered despite increasing awareness". Cellular and Molecular Immunology (Review). 10 (5): 383–392. doi:10.1038/cmi.2013.28. ISSN 1672-7681. PMC 4003198. PMID 23934026.
  15. ^ Ontiveros N, Hardy MY, Cabrera-Chavez F (2015). "Assessing of Celiac Disease and Nonceliac Gluten Sensitivity". Gastroenterology Research and Practice (Review). 2015: 1–13. doi:10.1155/2015/723954. PMC 4429206. PMID 26064097.
  16. ^ Priyanka, P; Gayam, S; Kupec, JT (2018). "The Role of a Low Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyol Diet in Nonceliac Gluten Sensitivity". Gastroenterology Research and Practice. 2018: 1561476. doi:10.1155/2018/1561476. PMC 6109508. PMID 30158962.
  17. ^ a b c d Volta U, De Giorgio R, Caio G, Uhde M, Manfredini R, Alaedini A (March 2019). "Nonceliac Wheat Sensitivity: An Immune-Mediated Condition with Systemic Manifestations". Gastroenterol Clin North Am (Review). 48 (1): 165–182. doi:10.1016/j.gtc.2018.09.012. PMC 6364564. PMID 30711208. Furthermore, a role for the FODMAP (eg, fructans) component of wheat as the sole trigger for symptoms is somewhat doubtful, because many patients with NCWS report resolution of symptoms after the withdrawal of wheat and related cereals, while continuing to ingest vegetables and fruits with high FODMAP content in their diets.59 On the whole, it is conceivable that more than one culprit may be involved in symptoms of NCWS (as they are currently defined), including gluten, other wheat proteins, and FODMAPs.60–62
  18. ^ Barrett JS (March 2017). "How to institute the low-FODMAP diet". Journal of Gastroenterology and Hepatology (Review). 32 Suppl 1: 8–10. doi:10.1111/jgh.13686. PMID 28244669. Common symptoms of IBS are bloating, abdominal pain, excessive flatus, constipation, diarrhea, or alternating bowel habit. These symptoms, however, are also common in the presentation of coeliac disease, inflammatory bowel disease, defecatory disorders, and colon cancer. Confirming the diagnosis is crucial so that appropriate therapy can be undertaken. Unfortunately, even in these alternate diagnoses, a change in diet restricting FODMAPs may improve symptoms and mask the fact that the correct diagnosis has not been made. This is the case with coeliac disease where a low-FODMAP diet can concurrently reduce dietary gluten, improving symptoms, and also affecting coeliac diagnostic indices. Misdiagnosis of intestinal diseases can lead to secondary problems such as nutritional deficiencies, cancer risk, or even mortality in the case of colon cancer.
  19. ^ Ferraris, Ronaldo P.; Choe, Jun-yong; Patel, Chirag R. (2018-08-21). "Intestinal Absorption of Fructose". Annual Review of Nutrition. 38: 41–67. doi:10.1146/annurev-nutr-082117-051707. ISSN 0199-9885. PMC 6457363. PMID 29751733.
  20. ^ Ferraris, Ronaldo P.; Choe, Jun-Yong; Patel, Chirag R. (21 August 2018). "Intestinal Absorption of Fructose". Annual Review of Nutrition. 38: 41–67. doi:10.1146/annurev-nutr-082117-051707. ISSN 1545-4312. PMC 6457363. PMID 29751733.
  21. ^ Storhaug CL, Fosse SK, Fadnes LT (October 2017). "Country, regional, and global estimates for lactose malabsorption in adults: a systematic review and meta-analysis". The Lancet. Gastroenterology & Hepatology. 2 (10): 738–746. doi:10.1016/S2468-1253(17)30154-1. PMID 28690131.
  22. ^ Bayless TM, Hanauer SB (2014). Advanced Therapy of Inflammatory Bowel Disease: Ulcerative Colitis. Vol. 1, 3e. PMPH-USA. pp. 250–. ISBN 978-1-60795-216-9.
  23. ^ a b c Gibson PR, Varney J, Malakar S, Muir JG (May 2015). "Food components and irritable bowel syndrome". Gastroenterology. 148 (6): 1158–74.e4. doi:10.1053/j.gastro.2015.02.005. PMID 25680668.
  24. ^ a b c d "The Monash University Low FODMAP diet". Melbourne, Australia: Monash University. 2012-12-18. Retrieved 2014-05-26.
  25. ^ "New research: Enzyme therapy can help reduce symptoms in IBS patients sensitive to galacto-oligosaccharides (GOS) present in legumes, soy milk and nuts".
  26. ^ Usai-Satta, Paolo; Lai, Mariantonia; Oppia, Francesco (January 17, 2022). "Lactose Malabsorption and Presumed Related Disorders: A Review of Current Evidence". Nutrients. 14 (3): 584. doi:10.3390/nu14030584. PMC 8838180. PMID 35276940. the impact of a lactose-restricted diet in patients with IBS is debated. Lactose is a component of the FODMAPs (highly fermentable oligo-, di-, monosaccharides and polyols) diet. Several studies confirmed the positive impact of a low FODMAP diet (LFD) in improving digestive symptoms in IBS. On the other hand, a lactose BT should be performed before an LFD in populations with a low prevalence of LM, avoiding an inappropriate exclusion of lactose in lactase-persistent IBS patients. Apart from FODMAPs, a lactose-restricted diet should be reserved for hypolactasic IBS patients. In conclusion, a restriction of lactose should be not systematically recommended in patients with IBS
  27. ^ Dinicolantonio, J. J.; Lucan, S. C. (2015). "Is Fructose Malabsorption a Cause of Irritable Bowel Syndrome?". Medical Hypotheses. 85 (3): 295–297. doi:10.1016/j.mehy.2015.05.019. PMC 4729202. PMID 26059250. Acute feeding studies have shown that almost one-third of patients with IBS are unable to tolerate large amounts of fructose
  28. ^ "What Is a Low-FODMAP Diet". WebMD. Retrieved 16 December 2019.
  29. ^ Staudacher HM, Whelan K (August 2017). "The low FODMAP diet: recent advances in understanding its mechanisms and efficacy in IBS". Gut (Review). 66 (8): 1517–1527. doi:10.1136/gutjnl-2017-313750. PMID 28592442. S2CID 3492917.
  30. ^ Gearry RB, Irving PM, Barrett JS, Nathan DM, Shepherd SJ, Gibson PR (February 2009). "Reduction of dietary poorly absorbed short-chain carbohydrates (FODMAPs) improves abdominal symptoms in patients with inflammatory bowel disease-a pilot study". Journal of Crohn's & Colitis. 3 (1): 8–14. doi:10.1016/j.crohns.2008.09.004. PMID 21172242.
  31. ^ Hou JK, Lee D, Lewis J (October 2014). "Diet and inflammatory bowel disease: review of patient-targeted recommendations". Clinical Gastroenterology and Hepatology (Review). 12 (10): 1592–600. doi:10.1016/j.cgh.2013.09.063. PMC 4021001. PMID 24107394. Even less evidence exists for the efficacy of the SCD, FODMAP, or Paleo diet. Furthermore, the practicality of maintaining these interventions over long periods of time is doubtful. At a practical level, adherence to defined diets may result in an unnecessary financial burden or reduction in overall caloric intake in patients who are already at risk for protein-calorie malnutrition.
  32. ^ Ontiveros N, Hardy MY, Cabrera-Chavez F (2015). "Assessing of Celiac Disease and Nonceliac Gluten Sensitivity". Gastroenterology Research and Practice (Review). 2015: 1–13. doi:10.1155/2015/723954. PMC 4429206. PMID 26064097. The literature suggests that FODMAPs and not gluten per se are the triggers of gastrointestinal symptoms in patients that fit most of the proposed NCGS definitions

Further readingEdit

External linksEdit