A Pilot Study on the Metabolic Impact of Mediterranean Diet in Type 2 Diabetes: Is Gut Microbiota the Key?

• Published in: Nutrients Vol. 13; no. 4; p. 1228
• Main Authors: Ismael, Shámila, Silvestre, Marta P, Vasques, Miguel, Araújo, João R, Morais, Juliana, Duarte, Maria Inês, Pestana, Diogo, Faria, Ana, Pereira-Leal, José B, Vaz, Joana, Ribeiro, Pedro, Teixeira, Diana, Marques, Cláudia, Calhau, Conceição
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 08.04.2021; MDPI
• Subjects: Alkaline phosphatase; Bacteria; Blood pressure; Body composition; Cholesterol; Diabetes; Diabetes mellitus; Diabetes mellitus (non-insulin dependent); Diet; Dietary fiber; Fatty acids; Feces; gut microbiota; Hemoglobin; Insulin; Insulin resistance; Intervention; Intestinal microflora; Lipoproteins; Mediterranean diet; Metabolism; Metabolites; Microbiota; Nutrition research; Phosphatase; Proteins; type 2 diabetes; Portugal; Mediterranean diet; gut microbiota; type 2 diabetes
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu13041228

The Mediterranean diet (MD) has been recommended for type 2 diabetes (T2D) treatment. The impact of diet in shaping the gut microbiota is well known, particularly for MD. However, the link between MD and diabetes outcome improvement is not completely clear. This study aims to evaluate the role of microbiota modulation by a nonpharmacological intervention in patients with T2D. In this 12-week single-arm pilot study, nine participants received individual nutritional counseling sessions promoting MD. Gut microbiota, biochemical parameters, body composition, and blood pressure were assessed at baseline, 4 weeks, and 12 weeks after the intervention. Adherence to MD [assessed by Mediterranean Diet Adherence Screener (MEDAS) score] increased after the intervention. Bacterial richness increased after 4 weeks of intervention and was negatively correlated with fasting glucose levels and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). to ratio also increased after 4 weeks. In contrast, glycated haemoglobin (HbA1c) and HOMA-IR were only decreased at the end of study. Alkaline phosphatase activity was assessed in fecal samples and was negatively correlated with HbA1c and positively correlated with bacterial diversity. The results of this study reinforce that MD adherence results in a better glycemic control in subjects with T2D. Changes in gut bacterial richness caused by MD adherence may be relevant in mediating the metabolic impact of this dietary intervention.