Prospective studies looking into the efficacy of specific diet restriction in functional dyspepsia (FD) are limited. Therefore, a study was conducted to evaluate the efficacy of low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet in FD, in comparison with traditional dietary advice (TDA).

The prospective, single-blind study randomized patients with FD (Rome IV) to low FODMAP diet (LFD) and TDA groups, for 4 weeks (phase I). This was followed by a phase II of 4-12 weeks, where the LFD group was advised systematic re-introduction of FODMAPs. Investigators evaluated symptom severity and quality of life with the help of the "Short-Form Nepean Dyspepsia Index (SF-NDI)." Primary outcome was symptomatic response (symptom score reduction of ≥ 50%) at 4 weeks.

A total of 184 patients were screened, of whom, 105 were randomized to the study groups – 54 to LFD group and 51 to TDA group.

• There was a significant reduction in SF-NDI symptom scores compared to baseline in both the groups at 4 weeks, with no significant difference in inter-group response rates [LFD: 66.7%; TDA: 56.9%; P = 0.32].
• Sub-group analysis revealed that patients with postprandial distress syndrome or bloating reported having significantly better symptomatic response with LFD (P = 0.04).
• SF-NDI quality of life scores showed a significant improvement in both groups.
• As per multivariate analysis, factors that predicted response to LFD included bloating and male gender.
• Adverse event (minor) incidence was similar in both groups.

In patients with FD, LFD and TDA are associated with significant improvements in symptomatic response and quality of life.

Patients with postprandial distress syndrome or bloating show a better response to LFD.

Dietary advice for patients with FD should be tailored based on FD subtype.

Source: Goyal O, Nohria S, Batta S, et al. Low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet versus traditional dietary advice for functional dyspepsia: a randomized controlled trial. J Gastroenterol Hepatol. 2022 Feb;37(2):301-309.