Influence of diet on gut microbiota, inflammation and type 2 diabetes mellitus. First experience with macrobiotic Ma-Pi 2 diet Francesco Fallucca 1 * Carmen Porrata 2 Sara Fallucca 3 Mario Pianesi 4 1 University La Sapienza, Rome, Italy 2 Finlay Institute, Havana, Cuba 3 Department of Endocrinology & Diabetes, University Campus Bio- Medico, Rome, Italy 4 International Association Un Punto Macrobiotico, Tolentino, Italy *Correspondence to: Francesco Fallucca, University La Sapienza, Via Nomentana 314, Rome, Italy. E-mail: francesco.fallucca@gmail.com Abstract Type 2 diabetes mellitus (T2DM) is a complex disorder influenced by both genetic and environmental factors. Recent studies have suggested that an imbalance of the intestinal microbiota may be involved in the development of several human diseases, including obesity and T2DM. The main regulators of the intestinal microbiota are age, ethnicity, the immune system and diet. A high-fat diet may induce dysbiosis, which can result in a low-grade inflammatory state, obesity and other metabolic disorders. Adding prebiotics to the diet may reduce inflam- mation, endotoxaemia and cytokine levels as well as improving insulin resistance and glucose tolerance. The administration of prebiotics such as fermentable die- tary fibres, promotes glucagon-like peptide 1 and peptide YY (anorexigenic) and decreases ghrelin (orexigenic). In a recent 21-day, intervention study in patients with T2DM, the effect of using the macrobiotic Ma-Pi 2 diet was investigated. Results suggested that it could induce a significant improvement in fasting blood glucose, plasma lipid fractions, plasma insulin and homeostasis. It is therefore possible that a diet rich in prebiotics and probiotics can play a role in T2DM management, probably due to positive intestinal microbiota modulation. However, this must be demonstrated by larger studies including randomized controlled trials that measure indicators of inflammation. Copyright © 2013 John Wiley & Sons, Ltd. Keywords Ma-Pi 2 macrobiotic diet; type 2 diabetes; prebiotic; probiotic; whole- grain cereals Introduction Type 2 diabetes mellitus (T2DM) is a global problem, which is expected to increase progressively in years to come, making it a major public health issue worldwide [1]. Risk factors for the development of T2DM include genetics, family history, ethnicity and excessive weight gain, with excessive weight gain the single most important factor [1]. Thus, T2DM can be defined as an obesity- driven global disease. Additionally, T2DM is associated with social class; the poorest people in the world are twice as likely to be affected by T2DM as afflu- ent people [1]. As a result, it is important that studies investigate ways of giving simple, pragmatic and cost-effective advice for changing diet and life- style (Table 1). REVIEW ARTICLE Received: 23 October 2013 Accepted: 19 December 2013 Copyright © 2013 John Wiley & Sons, Ltd. DIABETES/METABOLISM RESEARCH AND REVIEWS Diabetes Metab Res Rev 2014; 30(Suppl. 1): 48–54. Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/dmrr.2518