As patients without diagnosed gluten allergies continue to benefit from a gluten-free diet, researchers, medical professionals, and nutritionists alike are now turning to a related, but more prevalent, perpetrator of GI discomfort: FODMAPs. But, what are FODMAPs and how do they affect the microbiome? And, for those experiencing uncomfortable GI symptoms: could FODMAPs, not gluten, be the true culprit?
Low FODMAPs: The New Gluten Free?
Over the last 15 years, gluten has been accused of provoking a vast host of ailments, from gastrointestinal conditions to attention and mental health disorders. As a result of this negative association, and in pursuit of relief, an ever-increasing number of individuals are adopting a gluten-free diet. While strict adherence to a gluten-free lifestyle is essential for those with a diagnosed gluten allergy, persons with no such diagnosis are, nevertheless, discovering that a gluten-free diet can still facilitate some improvements to their gastrointestinal (GI) health. Taking this emerging pattern into consideration, researchers, medical professionals, and nutrition professionals alike have begun to consider another group of food constituents as possible contributors to GI discomfort: FODMAPs.
FODMAP is an acronym for “Fermentable Oligosaccharides, Disaccharides, Monosaccharides, And Polyols.” These fermentable carbohydrates are a class of dietary sugars that are resistant to the body’s innate digestive processes. As a result, FODMAPs are poorly absorbed within the GI tract and may be digested, or fermented, by the microbiome as they travel the gut. But, when microbes digest FODMAPs, gases are released in reaction, causing—for some individuals—an increase in the occurrence of GI discomforts, such as flatulence and bloating. Further pain, cramping, and diarrhea can also result from the presence of FODMAPs as they draw water into the GI lumen.
Collectively, the symptoms of gas, bloating, intermittent diarrhea, cramping, and pain are all common symptoms of IBS.1
IBS is the most prevalent “functional” GI disorder—“functional” because it is not caused by any known infection or by some other detectable defect. The symptoms associated with IBS are among the most predominant health concerns that prompt primary care providers to refer patients to gastroenterologists.2 And, although IBS affects approximately 14% of the global population, there is no effective medication or established treatment plan that successfully benefits a majority of those seeking relief.3
The low-FODMAP diet was developed by Dr. Peter Gibson and Dr. Susan Shepherd at Monash University in Australia. While searching for dietary solutions to IBS, Dr. Gibson and Dr. Shepherd were supported by the knowledge that individuals with IBS commonly restricted foods that they believed contributed to their symptoms—dairy, wheat, beans, cruciferous vegetables, and fruits, for example. They also recognized that consuming large amounts of polyols—i.e. sugar alcohols, such as sorbitol, mannitol, and erythritol—could cause IBS symptoms. An exhaustive review of these various factors led the doctors and their Australian research team to conclude that fermentable carbohydrates, or FODMAPs, were the common culprit in IBS-associated discomfort.
Based on biologic plausibility, as well as evidence from prospective trials that shows an improvement in symptoms in approximately 75% of patients, the low-FODMAP diet is now commonly used to treat IBS symptoms.4
Across several studies, a low-FODMAP diet has been compared to both a traditional IBS management diet and the mNICE diet (modified National Institute for Health and Care Excellence). In each comparative study, the low-FODMAP diet appeared to be the most effective for symptom relief, enhanced quality of life, or lowered anxiety, with approximately 75% of IBS patients experiencing improvement in real-world situations.5,6
Is a low-FODMAP diet right for you?
It is important to note FODMAPs are not all bad, especially not for those with a well-balanced microbiome. In fact, FODMAPs are found in a variety of very nutritious foods and contribute to several important physiological processes, including acting as prebiotics for healthy gut flora. However, for individuals experiencing digestive concerns or for persons hoping to reestablish healthy GI ecology, the low-FODMAP diet may be a short-term step in a healthy direction.
For those who are concerned that restricting FODMAPs in the diet will also reduce beneficial prebiotic fiber intake, there are supplemental options—including partially-hydrolyzed guar gum (PHGG)—that have been certified as low-FODMAP by Monash University. PHGG is a water-soluble, non-viscous, non-gelling dietary fiber composed of long-chains of galactose and mannose carbohydrates—galactomannan—that are derived from the seeds of the guar plant. Due to its medium length, PHGG ferments more slowly in the intestinal tract than shorter prebiotic fibers without producing excessive gas or bloating. PHGG, when compared to high-FODMAP prebiotic fibers, is also well-tolerated by sensitive individuals.7,8
As always, any person with dietary and digestive concerns should work closely with a medical team, including a dietitian, to develop a customized strategy that addresses GI health issues, more closely identifies the exact source of difficulty, and ensures that no nutrient deficiencies develop.†
References
1. Moayyedi P, Mearin F, Azpiroz F, et al. United European Gastroenterol J. 2017;5(6):773-788.
2. Häuser W, Layer P, Henningsen P, Kruis W. Dtsch Arztebl Int. 2012;109(5):83–94.
3. Ford AC, Lacy BE, Talley NJ. N Engl J Med. 2017 Jun 29; 376(26):2566-2578.
4. Werlang ME, Palmer WC, Lacy BE. Gastroenterol Hepatol (N Y). 2019;15(1):16–26.
5. Eswaran SL, Chey WD, Han-Markey T, Ball S, Jackson K. Am J Gastroenterol. 2016;111(12):1824–1832.
6. Altobelli E, Del Negro V, Angeletti PM, Latella G. Nutrients. 2017;9(9):E940.
7. Parisi G, Bottona E, Carrara M, et al. Dig Dis Sci. 2005;50(6):1107–1112. 7
8. Niv E, Halak A, Tiommny E, et al. Nutr Metab (Lond). 2016;13:10.
