FODMAP is an acronym that stands for Fermentable Oligo-, Di- and Mono-saccharides And Polyols. They are highly fermentable and poorly absorbed short-chain carbohydrates and polyols. The acronym was created in the early 2000s, and most of the initial scientific work related to FODMAPs and their impact on digestive health comes from Monash University in Melbourne, Australia.
What are FODMAPs?
FODMAPs include oligosaccharides (fructans, fructo-oligosaccharides (FOS) and galacto-oligosacchrides = GOS), disaccharides (lactose), monosaccharides (fructose), and polyols (sorbitol, mannitol, maltitol, xylitol, polydextrose, and isomalt). The list of dietary sugar alcohols (polyols) includes compounds widely used by the food industry as thickeners and sweeteners. Lactose belongs to FODMAPs only in individuals showing non-persistence of high lactase levels, which is a highly variable percentage of subjects in different populations.
How do FODMAPs affect GI health?
FODMAPs are typically poorly absorbed in the small intestine. They are often osmotically-active molecules, meaning that they draw water into the GI tract, and they usually are rapidly fermented by the local microbiota.
FODMAPs also have important physiological effects: they increase stool bulk, enhance calcium absorption, modulate immune function, and some of them may even contribute to healthy levels of serum cholesterol, triacylglycerols, and phospholipids. They selectively stimulate the growth of some beneficial microbial groups such as Bifidobacteria (prebiotic effect). Due to their capacity to stimulate the growth of nonpathogenic intestinal microflora, FOS and GOS are increasingly included in food products and infant formulas. Furthermore, the fermentation of small, fermentable carbohydrates in the colon results in the production of short-chain fatty acids (SCFAs = acetate, propionate, and butyrate) that have a trophic effect on the colon intestinal barrier by increasing energy production and healthy cell proliferation.
Why are some people avoiding FODMAPs?
For individuals with a sensitive GI tract, ingesting these foods can trigger GI discomfort, as they are known to increase small intestinal water volume, colonic gas production, intestinal distension, and intestinal motility. This can trigger intense pain and irregular bowel movements. For these individuals, implementing a low FODMAP strategy may contribute to a relief of GI discomfort.
What is the best way to implement a low FODMAP dietary strategy?
The FODMAP diet is better implemented with a healthcare practitioner as it is sometimes difficult to follow on one’s own and because it requires removing important functional foods from the diet. Tackling it on your own could result in nutrient deficiencies.
What is the role of the healthcare practitioner in the implementation of a FODMAP diet?
The role of the practitioner is to thoroughly explain the low FODMAP dietary strategy, to support the patient at every phase of the diet, and to ensure patients do not develop long term nutritional deficiencies by recommending adequate supplementation with vitamins, minerals, and GI support supplements.
How can I get more information about the FODMAP diet?
Monash University has developed ample resources about the FODMAP diet, and you can discuss these with your primary healthcare practitioner to determine the possible relevance of this dietary strategy in the support of your digestive health.