Impact of a Mediterranean Diet Supplemented with Extra Virgin Olive Oil on Gut Microbiota in Fibromyalgia: A...

Fibromyalgia is a chronic syndrome associated with pain, fatigue, and cognitive symptoms, often linked to gut microbiota alterations. The Mediterranean Diet (MD), particularly extra-virgin olive oil (EVOO), has antioxidant and anti-inflammatory properties that may beneficially modulate the microbiota. We conducted a prospective, randomized, double-blind, placebo-controlled clinical trial that included 250 women (206 with fibromyalgia, 44 controls). Participants followed a MD supplemented with EVOO or refined olive oil (placebo) for six months. Microbiota composition was analyzed at four time points (T0-T3) by 16S rRNA sequencing (V3-V4). At baseline, fibromyalgia patients exhibited reduced microbial diversity compared to controls. While global diversity did not change after intervention, specific taxa increased significantly with EVOO, including Bacteroides fragilis, Anaerotruncus colihominis, Adlercreutzia equolifaciens, and butyrate producers such as Faecalibacterium prausnitzii, Roseburia intestinalis, and Agathobacter. These shifts suggest EVOO supplementation might promote anti-inflammatory and metabolic bacteria, suggesting diet as a complementary strategy to modulate gut microbiota in fibromyalgia.