Glycine Metabolism and Its Alterations in Obesity and Metabolic Diseases
Anaïs Alves,
Arthur Bassot,
Anne-Laure Bulteau,
Luciano Pirola,
Béatrice Morio
Affiliations
Anaïs Alves
Université de Lyon, Laboratoire de Recherche en Cardiovasculaire Métabolisme Diabétologie et Nutrition, Institut National de la Santé et de la Recherche Médicale, Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées de Lyon, Université Claude Bernard Lyon 1, Unite Mixte de Recherche 1060, 69310 Pierre Bénite, France
Arthur Bassot
Université de Lyon, Laboratoire de Recherche en Cardiovasculaire Métabolisme Diabétologie et Nutrition, Institut National de la Santé et de la Recherche Médicale, Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées de Lyon, Université Claude Bernard Lyon 1, Unite Mixte de Recherche 1060, 69310 Pierre Bénite, France
Anne-Laure Bulteau
Université de Lyon, Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Superieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard Lyon 1, Unite Mixte de Recherche 5242, 69007 Lyon, France
Luciano Pirola
Université de Lyon, Laboratoire de Recherche en Cardiovasculaire Métabolisme Diabétologie et Nutrition, Institut National de la Santé et de la Recherche Médicale, Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées de Lyon, Université Claude Bernard Lyon 1, Unite Mixte de Recherche 1060, 69310 Pierre Bénite, France
Béatrice Morio
Université de Lyon, Laboratoire de Recherche en Cardiovasculaire Métabolisme Diabétologie et Nutrition, Institut National de la Santé et de la Recherche Médicale, Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées de Lyon, Université Claude Bernard Lyon 1, Unite Mixte de Recherche 1060, 69310 Pierre Bénite, France
Glycine is the proteinogenic amino-acid of lowest molecular weight, harboring a hydrogen atom as a side-chain. In addition to being a building-block for proteins, glycine is also required for multiple metabolic pathways, such as glutathione synthesis and regulation of one-carbon metabolism. Although generally viewed as a non-essential amino-acid, because it can be endogenously synthesized to a certain extent, glycine has also been suggested as a conditionally essential amino acid. In metabolic disorders associated with obesity, type 2 diabetes (T2DM), and non-alcoholic fatty liver disease (NAFLDs), lower circulating glycine levels have been consistently observed, and clinical studies suggest the existence of beneficial effects induced by glycine supplementation. The present review aims at synthesizing the recent advances in glycine metabolism, pinpointing its main metabolic pathways, identifying the causes leading to glycine deficiency—especially in obesity and associated metabolic disorders—and evaluating the potential benefits of increasing glycine availability to curb the progression of obesity and obesity-related metabolic disturbances. This study focuses on the importance of diet, gut microbiota, and liver metabolism in determining glycine availability in obesity and associated metabolic disorders.