Citation: De Giuseppe, R.; Loperfido, F.; Cerbo, R.M.; Monti, M.C.; Civardi, E.; Garofoli, F.; Angelini, M.; Maccarini, B.; Sommella, E.; Campiglia, P.; et al. LIMIT: LIfestyle and Microbiome InTeraction Early Adiposity Rebound in Children, a Study Protocol. Metabolites 2022, 12, 809. https://doi.org/10.3390/ metabo12090809 Academic Editors: Clint Lee Gray, Lifeng Peng, Timothy Regnault and Michal Ciborowski Received: 8 July 2022 Accepted: 24 August 2022 Published: 28 August 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). metabolites H OH OH Study Protocol LIMIT: LIfestyle and Microbiome InTeraction Early Adiposity Rebound in Children, a Study Protocol Rachele De Giuseppe 1, * ,† , Federica Loperfido 1,† , Rosa Maria Cerbo 2 , Maria Cristina Monti 3 , Elisa Civardi 2 , Francesca Garofoli 2 , Micol Angelini 2 , Beatrice Maccarini 1 , Eduardo Sommella 4 , Pietro Campiglia 4 , Laura Bertuzzo 5 , Marcello Chieppa 6 , Stefano Ghirardello 2,‡ and Hellas Cena 1,7,‡ 1 Laboratory of Dietetics and Clinical Nutrition, Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Via Bassi 21, 27100 Pavia, Italy 2 Neonatal Unit and Neonatal Intensive Care Unit, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy 3 Department of Public Health, Experimental and Forensic Medicine—Unit of Biostatistics and Clinical Epidemiology, University of Pavia, 27100 Pavia, Italy 4 Department of Pharmacy, University of Salerno, Fisciano, 84084 Salerno, Italy 5 GlaxoSmithKline (GSK) Consumer Healthcare, Haleon Group, Via Zambeletti s.n.c. 20021 Baranzate, Italy 6 Department of Biological and Environmental Sciences and Technologies (DISTEBA), University of Salento, 73100 Lecce, Italy 7 Clinical Nutrition and Dietetics Service, Unit of Internal Medicine and Endocrinology, ICS Maugeri IRCCS, 27100 Pavia, Italy * Correspondence: rachele.degiuseppe@unipv.it † These authors contributed equally to this work. ‡ These authors contributed equally to this work. Abstract: Childhood obesity is a strong predictor of adult obesity with health and economic con- sequences for individuals and society. Adiposity rebound (AR) is a rise in the Body Mass Index occurring between 3 and 7 years. Early adiposity rebound (EAR) occurs at a median age of 2 years and predisposes to a later onset of obesity. Since obesity has been associated with intestinal dysbiosis, we hypothesize that EAR could be related to early microbiome changes due to maternal/lifestyle changes and environmental exposures, which can increase the unhealthy consequences of childhood obesity. LIMIT is a prospective cohort study that aims at identifying the longitudinal interplay between infant gut microbiome, infant/maternal lifestyle, and environmental variables, in children with EAR vs. AR. Methods. The study evaluated 272 mother-infant pairs, enrolled at an Italian neonatal unit, at different time points (T0, at delivery; T1, 1 month; T2, 6 months; T3, 12 months; T4, 24 months; T5, 36 months after birth). The variables that were collected include maternal/infant anthropometric measurements, lifestyle habits, maternal environmental endocrine disruptor expo- sure, as well as infant AR. The LIMIT results will provide the basis for early identification of those maternal and infant modifiable factors on which to act for an effective and personalized prevention of childhood obesity. Keywords: childhood obesity; early adiposity rebound; microbiome; lifestyle; nutrition 1. Introduction Obesity is a worldwide epidemic and is one of the most critical public health challenges. The number of people with obesity has tripled in Europe compared to 40 years ago [1]. In the certain EU Member States, obesity prevalence in children is reaching well over 30% with a significant impact on their health, affecting physical and psychological abilities, which can further worsen health costs and quality of life in adulthood [1,2]. Indeed, obesity is already responsible for 2–8% of the health costs and 10–13% of the deaths in different parts of Europe [1]. Given that childhood obesity is a strong predictor of obesity in adulthood [3,4] and that its prevalence is projected to increase further by 2030, obesity poses a major threat to the Metabolites 2022, 12, 809. https://doi.org/10.3390/metabo12090809 https://www.mdpi.com/journal/metabolites