Effectiveness of an 8-Week Low-FODMAP Diet in Improving Gastrointestinal Symptoms and Health-Related Quality of Life in Adults with Irritable Bowel Syndrome: A Randomized Controlled Trial
DOI:
https://doi.org/10.29070/kq12ej70Keywords:
Irritable bowel syndrome, Low-FODMAP diet, Diet therapy, Functional gastrointestinal disorders, Rome IV criteria, Randomized controlled trial, Gastrointestinal symptoms, Quality of lifeAbstract
Background: Irritable bowel syndrome (IBS) is one of the most prevalent disorders of gut–brain interaction and is characterized by recurrent abdominal pain associated with altered bowel habits. Because dietary triggers frequently exacerbate IBS symptoms, dietary modification has become an important component of clinical management. Restriction of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) has emerged as an evidence-based therapeutic strategy; however, further randomized controlled studies are needed to evaluate its effectiveness in different populations.
Objective: To evaluate the effectiveness of an 8-week Low-FODMAP dietary intervention on gastrointestinal symptoms and patient-reported outcomes in adults with IBS.
Methods: A single-blind randomized controlled trial was conducted between March and May 2025. Sixty adults diagnosed with IBS according to the Rome IV criteria were randomly allocated to either a Low-FODMAP diet group (n = 30) or a standard dietary advice group (n = 30). Participants in the intervention group received individualized dietary counselling and followed a structured Low-FODMAP diet for eight weeks, whereas the control group continued their habitual diet with general healthy eating advice. Gastrointestinal symptoms were assessed at baseline and after the intervention using a validated symptom questionnaire. Within-group comparisons were performed using paired t-tests, and statistical significance was established at p < 0.05.
Results : Participants assigned to the Low-FODMAP diet demonstrated significant improvement in 14 of the 17 assessed symptom domains following the intervention. Marked improvements were observed in abdominal discomfort, bloating, bowel habits, excessive gas, stool consistency, and overall symptom burden. Paired t-test values ranged from 2.504 to 8.226 (p < 0.05). In contrast, participants receiving standard dietary advice showed minimal changes, with statistically significant improvement observed in only two symptom domains. Crosstab analyses further demonstrated significant reductions in bowel urgency, harder stools, and excessive gas in the intervention group, whereas no significant improvements were observed in the control group.
Conclusions: An eight-week Low-FODMAP dietary intervention significantly improved gastrointestinal symptoms and patient-reported outcomes among adults with IBS. These findings support the integration of structured Low-FODMAP dietary counselling into routine clinical management of IBS. Larger multicentre studies with longer follow-up are warranted to determine long-term effectiveness and sustainability.
Downloads
References
1. Altobelli, E., Del Negro, V., Angeletti, P. M., Latella, G., & Giuliani, A. R. (2017). Low-FODMAP diet improves irritable bowel syndrome symptoms: A meta-analysis. Nutrients, 9(9), 940.
2. Black, C. J., Drossman, D. A., Talley, N. J., Ruddy, J., Ford, A. C., & Sperber, A. D. (2021). Functional gastrointestinal disorders: Advances in understanding and management. Lancet Gastroenterology & Hepatology, 6(10), 866–880.
3. Böhn, L., Störsrud, S., Liljebo, T., Collin, L., Lindfors, P., & Simre´n, M. (2015). Diet low in FODMAPs reduces symptoms of irritable bowel syndrome as well as traditional dietary advice: A randomized controlled trial. Gastroenterology, 149(6), 1399–1407.
4. Canavan, C., West, J., & Card, T. (2014). The epidemiology of irritable bowel syndrome. Clinical Epidemiology, 6, 71–80.
5. Ford, A. C., Lacy, B. E., & Talley, N. J. (2020). Irritable bowel syndrome. New England Journal of Medicine, 382(10), 965–975.
6. Gibson, P. R., & Shepherd, S. J. (2010). Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach. Journal of Gastroenterology and Hepatology, 25(2), 252–258.
7. Halmos, E. P., Power, V. A., Shepherd, S. J., Gibson, P. R., & Muir, J. G. (2014). A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology, 146(1), 67–75.
8. Halmos, E. P., Christophersen, C. T., Bird, A. R., Shepherd, S. J., Gibson, P. R., & Muir,
J. G. (2015). Diets that differ in their FODMAP content alter the colonic luminal microenvironment. Gut, 64(1), 93–100.
9. Mayer, E. A., Labus, J. S., Tillisch, K., Cole, S. W., & Baldi, P. (2021). Towards a systems view of IBS. Nature Reviews Gastroenterology & Hepatology, 18(7), 451–463.
10. Muir, J. G., & Gibson, P. R. (2019). The low FODMAP diet for treatment of irritable bowel syndrome and other gastrointestinal disorders. Gastroenterology & Hepatology, 15(5), 281–288.
11. Snoek, H. M., Jansen, A., & van den Hout, M. A. (2018). The influence of food intake on mood and psychological well-being. Appetite, 128, 72–79.
12. Staudacher, H. M., Whelan, K., Irving, P. M., & Lomer, M. C. (2012). Comparison of symptom response following advice for a diet low in FODMAPs versus standard dietary advice in patients with IBS. Journal of Human Nutrition and Dietetics, 25(5), 450–458.
13. Staudacher, H. M., Lomer, M. C. E., Anderson, J. L., Barrett, J. S., Muir, J. G., Irving, P. M., & Whelan, K. (2017). Mechanisms and efficacy of dietary FODMAP restriction in IBS. Nature Reviews Gastroenterology & Hepatology, 14(1), 36–47.
14. Tuck, C. J., Biesiekierski, J. R., Schmid-Grendelmeier, P., & Pohl, D. (2018). Food intolerances. Nutrients, 10(10), 1409.
