The Long-Term Effects of a Low–Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols Diet for Irritable Bowel Syndrome Management

Short-term studies indicate that low–fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diets (LFDs) can improve symptoms for patients with irritable bowel syndrome (IBS). However, long-term (≥6 mo) effectiveness, safety, and sustainability of an LFD are not well understood and remain controversial. The primary purpose of the current review was to consider the published research on the effectiveness, safety, and sustainability of an LFD for patients with IBS. The secondary aim was to develop an infographic for dissemination to outpatient registered dietitian nutritionists and other healthcare professionals who work with patients with IBS. Three electronic databases (PubMed, Scopus, and Web of Science) were searched through December 2022, using the terms irritable bowel syndrome, FODMAP, and long-term. Following article selection, a total of 14 studies were included. Nine of 9 studies reported significant improvements in symptoms, 7 of 7 studies showed significant improvements in bowel habits, 1 of 1 study showed significantly improved disease course, and 6 of 6 studies showed significantly improved quality of life, compared to baseline. One study showed that improvement in gastrointestinal symptoms was significantly correlated with improvements in quality of life. Two of 3 studies and body composition measures indicated that nutritional adequacy was not compromised. Two of 2 studies showed that gut microbiota did not change, but 1 study showed decreased short-chain fatty acids. Adherence rates ranged from 50% to 82%, and 1 study showed that greater adherence was significantly correlated with improved IBS symptoms. Three of 3 studies showed that better adherence to an LFD was associated with improved symptom relief, and 70%–89% of participants reported satisfaction with the LFD for IBS management. The main difficulties reported were the higher expense and adhering to the diet when eating at restaurants, with family and friends, or while traveling. Overall, a long-term LFD for IBS management can be effective, safe, and sustainable.