Pastor Villaescusa, BelénCaballero Villarraso, JavierCañete, M. DoloresHoyos, RaúlMaldonado, JoséBueno, GloriaLeis Trabazo, María RosauraCañete, RamónAguilera, Concepción M.2017-10-202017-10-202016-07-18Pastor-Villaescusa, Belén, Javier Caballero-Villarraso, M. Dolores Cañete, Raúl Hoyos, José Maldonado, Gloria Bueno, Rosaura Leis, Ángel Gil, Ramón Cañete, and Concepción M. Aguilera. 2016. "Evaluation Of Differential Effects Of Metformin Treatment In Obese Children According To Pubertal Stage And Genetic Variations: Study Protocol For A Randomized Controlled Trial". Trials 17 (1). doi:10.1186/s13063-016-1403-41745-6215http://hdl.handle.net/10347/15918Overweight and obesity are considered to be serious public health problems. In pediatric populations, insulin resistance, dyslipidemia, and hypertension associated with obesity occur with increased frequencies. Metformin is an oral anti-hyperglycemic agent that has been demonstrated to be efficacious in the treatment of diabetic and non-diabetic obese adults. A considerable amount of pharmacogenetic research has demonstrated that genetic variation is one of the major factors affecting metformin response. Additionally, potential microbiota-mediated mechanisms of metformin effect have been recently described. However, scant work has been conducted in children, with no attention being paid to the potential effects of pubertal development. Thus, the main objective of the present study is to evaluate the effect of metformin treatment together with lifestyle recommendations in a randomized control trial (RCT) of obese children according to pubertal stage, genetic variants and signature of gut microbiotaeng© 2016 Pastor-Villaescusa et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise statedMetforminChildrenObesityPubertyLifestyle interventionMicrobiotaPolymorphismsjournal article10.1186/s13063-016-1403-4open access