UK: In a new study, it was found that traditional dietary advice (TDA), low FODMAP diet (LFD), and gluten-free diet (GFD) are all effective treatments for non-constipated irritable bowel syndrome (IBS), however, TDA is the most cost-effective and convenient for patients. The findings of this study were published in Clinical Gastroenterology and Hepatology on 28th February 2022.
Despite limited or low-quality data, many diets are advocated as first-line therapy for non-constipated irritable bowel syndrome. Anupam Rej and colleagues conducted a randomized experiment comparing typical dietary guidance to the low FODMAP and gluten-free diets.

For this study patients with Rome IV-defined, non-constipated IBS were randomly assigned to one of three diets: TDA, LFD, or GFD (the latter allowing for minimal gluten cross-contamination). The primary outcome was the clinical response after four weeks of dietary intervention, as defined by a 50-point decrease in IBS symptom severity (IBS-SSS). Secondary endpoints included: I change in individual IBS-SSS items among clinical responders, ii) food-related quality of life and acceptability with dietary therapy, iii) changes in the nutritional intake, iv) changes in stool dysbiosis index, and v) baseline factors associated with clinical response.
The results of this study stated as follow:
1. The primary goal of a 50-point reduction in IBS-SSS was attained by 42% of those who used TDA, 55% of those who tried LFD, and 58% of those who tried GFD.
2. Regardless of diet, respondents improved on IBS-SSS items in the same manner.
3. Individuals found TDA to be less expensive, less time-consuming to buy for, and simpler to adhere to when dining out than the GFD and LFD.
4. TDA was also less difficult to adopt into daily living than LFD.
5. The overall reductions in micro- and macronutrient consumption did not differ substantially between diets.
6. However, as compared to the GFD and TDA groups, the LFD group exhibited the highest reduction in total FODMAP content.
7. Stool dysbiosis index changes were comparable across diets, with 22-29% exhibiting reduced dysbiosis, 35-39% showing no change, and 35-40% indicating increased dysbiosis.
8. The baseline clinical features and stool dysbiosis score did not predict nutritional treatment response.
In conclusion, TDA is the most patient-friendly in terms of cost and convenience. Researchers propose TDA to be the first-choice dietary therapy in non-constipated IBS, with an GFD and LFD reserved for particular patient preferences and professional dietetic input.
Reference:
Rej, A., Sanders, D. S., Shaw, C. C., Buckle, R., Trott, N., Agrawal, A., & Aziz, I. (2022). Efficacy and Acceptability of Dietary Therapies in Non-Constipated Irritable Bowel Syndrome: A Randomized Trial of Traditional Dietary Advice, the Low FODMAP Diet and the Gluten-Free Diet. In Clinical Gastroenterology and Hepatology. Elsevier BV. https://doi.org/10.1016/j.cgh.2022.02.045
Keywords: diet, constipation, stool dysbiosis, gluten-free, therapy, nutrition, irritable bowel syndrome, inflammation, irritation, infection, traditional,nutrition,microbiome, Anupam Rej, IBS