Four IBS Diet Strategies Show Distinct Profiles In Review

Key Takeaways

• Low FODMAP interventions showed relatively consistent short-term response, but pooled analysis did not show a significant advantage over other dietary approaches.
• Mediterranean-based interventions appeared promising at longer follow-up in individual trials, while traditional dietary advice was more acceptable but showed lower pooled response.
• Starch- and sucrose-reduced diets showed favorable findings in selected comparisons, gluten-free diets were inconsistent overall, and no serious adverse events were reported.

No single dietary category emerged as the clear overall leader for adults with irritable bowel syndrome in this systematic review and meta-analysis of 10 randomized trials involving 939 participants. Low FODMAP plans, Mediterranean-based approaches, traditional dietary advice, and emerging diets such as starch- and sucrose-reduced patterns each showed strengths in different comparisons, while gluten-free diets were inconsistent overall. Symptom response, acceptability, safety, and practical use did not converge on one uniform winner. The findings instead pointed to trade-offs across short-term efficacy, acceptability, and longer-term practicality.

The investigators evaluated adults with IBS in 10 randomized controlled trials totaling 939 participants. The review covered trials published or registered between 2019 and 2025 and used random-effects meta-analysis for pooled comparisons. Mediterranean-based interventions included the Mediterranean diet and Mediterranean low-FODMAP variants, while emerging approaches included starch- and sucrose-reduced and gluten-free diets. Risk of bias was assessed with the Cochrane tool, although findings remained uneven across categories. The analysis was framed around outcomes across diets rather than a search for a single winning strategy.

Low FODMAP interventions showed short-term responder rates ranging from 34% to 78% across individual trials. Pooled analysis found no significant difference versus other dietary interventions, with RR 1.04, 95% CI 0.91–1.19, P = 0.55, and I2 = 0%. Traditional dietary advice produced responder rates of 42% to 48.1% in individual trials. Its pooled response was lower than that of comparator diets, with RR 0.75, 95% CI 0.64–0.88, P = 0.0005, and I2 = 0%. These results separated pooled efficacy from acceptability rather than identifying one clearly dominant option.

Mediterranean-based interventions, especially the Mediterranean low-FODMAP approach, showed promising longer-term findings in individual trials. Follow-up response rates reached 81.5% and 70.4%, and one recent randomized trial found superiority over traditional dietary advice, with P = 0.007 and P = 0.004. Starch- and sucrose-reduced diets also showed favorable efficacy in habitual-diet-controlled comparisons. In one head-to-head trial, they were non-inferior to low FODMAP and had better long-term adherence in descriptive follow-up data. Gluten-free diets remained inconsistent, and pooled analysis showed no significant advantage over comparators, with RR 1.19, 95% CI 0.83–1.70, and I2 = 0%. Overall, the trial-level findings varied across diet categories.

Across included studies, traditional dietary advice had the highest acceptability, and no serious adverse events were reported. The authors concluded that the four dietary categories differed in efficacy, acceptability, and safety profiles, without one approach proving uniformly superior across all reported domains. Traditional dietary advice was described as carrying practical advantages despite lower pooled response than some comparators. The authors added that larger, well-designed randomized trials are needed to confirm the findings and clarify subgroup-specific responses.