A new clinical trial has found that the Mediterranean diet may offer superior relief for people with irritable bowel syndrome (IBS) compared with standard dietary guidance, suggesting a potential shift in how the condition is managed. Researchers conducted a randomized noninferiority trial, involving 139 adults from across the United Kingdom. Participants, with an average age of 40 years and mostly women, were enrolled through an online virtual platform.
The study compared six weeks of following the Mediterranean diet, which emphasizes fruits, vegetables, whole grains, fish, olive oil, and nuts, with traditional dietary advice (TDA), the current first-line recommendation for IBS. Typically, when TDA fails, patients progress to the restrictive low-FODMAP diet, which is effective but difficult to maintain.
Results and Clinical Outcomes
The researchers defined clinical response as a 50-point or greater reduction on the IBS Symptom Severity Scale (IBS-SSS). After six weeks, 62 percent of participants following the Mediterranean diet reached that threshold, compared with 42 percent in the TDA group. The difference of 20 percentage points favoured the Mediterranean diet and demonstrated both noninferiority and superiority (P = 0.017).
Participants on the Mediterranean diet also showed a greater average reduction in symptom severity, with an improvement of 101.2 points on the IBS-SSS compared with 64.5 points in the TDA group (CI: -70.5 to -2.8; P=0.034). No significant differences were observed between groups in mood, somatic symptom reporting, overall quality of life, or diet satisfaction. However, adherence scores on the Mediterranean Diet Adherence Screener significantly increased for those in the Mediterranean group (P < 0.001).
Implications for IBS Management
While the researchers noted that the study’s short duration leaves the long-term effects uncertain, the findings suggest that the Mediterranean diet could serve as a practical, sustainable first-line dietary option for IBS management.
Reference
Bamidele JO et al. The mediterranean diet for irritable bowel syndrome: a randomized clinical trial. Annals of Internal Medicine. 2025; doi:10.7326/ANNALS-25-01519.
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