The Low FODMAP Diet: Many Question Marks for a Catchy Acronym

Abstract

FODMAP, “Fermentable Oligo-, Di- and Mono-saccharides And Polyols”, is a heterogeneous group of highly fermentable but poorly absorbed short-chain carbohydrates and polyols. Dietary FODMAPs might exacerbate intestinal symptoms by increasing small intestinal water volume, colonic gas production, and intestinal motility. In recent years the low-FODMAP diet for treatment of irritable bowel syndrome (IBS) has gained increasing popularity. In the present review we aim to summarize the physiological, clinical, and nutritional issues, suggesting caution in the prolonged use of this dietary treatment on the basis of the existing literature. The criteria for inclusion in the FODMAPs list are not fully defined. Although the low-FODMAP diet can have a positive impact on the symptoms of IBS, particularly bloating and diarrhea, the quality of the evidence is lower than optimal, due to frequent methodological flaws, particularly lack of a proper control group and/or lack of blinding. In particular, it remains to be proven whether this regimen is superior to conventional IBS diets. The drastic reduction of FODMAP intake has physiological consequences, e.g., on the intestinal microbiome and colonocyte metabolism, which are still poorly understood. A low-FODMAP diet imposes an important restriction of dietary choices due to the elimination of some staple foods, such as wheat derivatives, lactose-containing dairy products, many vegetables and pulses, and several types of fruits. For this reason, patients may be at risk of reduced intake of fiber, calcium, iron, zinc, folate, B and D vitamins, and natural antioxidants. The nutritional risk of the low-FODMAP diet may be higher in persons with limited access to the expensive, alternative dietary items included in the low-FODMAP diet.

Low fermentable oligosaccharides, disaccharides, monosaccharides, and polypols diet and irritable bowel syndrome in Asia

“…sorbitol) (Fig. ) . FODMAP is less absorbable by the intestine due to a lack of brush border enzymes or the presence of low‐capacity epithelial transporters, such as GLUT‐2, and are highly fermentable by gut microbiota into short‐chain fatty acids (SCFAs), including acetate, propionate, and butyrate.…”

“…As a result, FODMAP increases water volume and intestinal gas production and promotes intestinal motility. In addition, it can increase calcium absorption, lower serum cholesterol and triacylglycerols levels, and modify gut immune function …”

Carbohydrate Maldigestion and Malabsorption

“…1 Recently, there has been much focus on fermentable, oligosaccharides, monosaccharides, and polyols, a group of compounds that includes fructans, lactose, fructose, and sorbitol, and that are poorly absorbed yet readily fermentable. 4 Their fermentation by anaerobic bacteria in the colon ultimately leads to the production of lactic acid and the short-chain fatty acids (SCFAs) acetate, propionate, and butyrate (with an accompanying lowering of colonic luminal pH) and the gases hydrogen, methane, and carbon dioxide ( Figure 1). SCFAs exert a variety of effects on motility and intestinal secretion, which can lead to the development of abdominal cramps and diarrhea ( Figure 1).…”

Effectiveness of Two Dietary Approaches on the Quality of Life and Gastrointestinal Symptoms of Individuals with Irritable Bowel Syndrome

“…FODMAPs (fermentable oligosaccharides, monosaccharaides, disaccharides and polyols) have a slow and incomplete absorption in the small intestine, contributing to an increase of the osmotic gradient in the lumen and lead to bacterial fermentation that are part of intestinal microbiota [10]. A diet rich in FODMAPs leads to an increased presence of water and gas in the intestinal lumen, which in combination with other factors (of physiological, psychosocial nature and/or from an environmental source) can trigger symptomatology characteristic of an IBS diagnosis [10,11].…”

“…This evidence supports a low FODMAP diet compounds as an effective dietary approach to IBS treatment. Despite recent evidence, some aspects of this diet are still controversial, namely its efficiency when compared to a standard diet, maintenance in a medium/long term and its nutritional efficacy [11]. However, studies performed in populations of Mediterranean origin are scarce.…”