Mahmoud A Mohammad1, Agneta L Sunehag, Morey W Haymond. 1. Department of Pediatrics, Children's Nutrition Research Center, US Department of Agriculture/Agricultural Research Service, Baylor College of Medicine, Houston, Texas.
Abstract
UNLABELLED: Mammary gland (MG) de novo lipogenesis contributes significantly to milk fat in animals but little is known in humans. OBJECTIVE: To test the hypothesis that the incorporation of (13)C carbons from [U-(13)C]glucose into fatty acids (FA) and glycerol in triglycerides (TG) will be greater: 1) in milk than plasma TG, 2) during a high-carbohydrate (H-CHO) diet than high-fat (H-FAT) diet, and 3) during feeding than fasting. Seven healthy, lactating women were studied on two isocaloric, isonitrogenous diets. On one occasion, subjects received diets containing H-FAT or H-CHO diet for 1 wk. Incorporation of (13)C from infused [U-(13)C]glucose into FA and glycerol was measured using GC-MS and gene expression in RNA isolated from milk fat globule using microarrays. Incorporation of (13)C2 into milk FA increased with increased FA chain length from C2:0 to C12:0 but progressively declined in C14:0 and C16:0 and was not detected in FA>C16. During feeding, regardless of diets, enrichment of (13)C2 in milk FA and (13)C3 in milk glycerol were ∼ 3- and ∼ 7-fold higher compared with plasma FA and glycerol, respectively. Following an overnight fast during H-CHO and H-FAT diets, 25 and 6%, respectively, of medium-chain FA (MCFA, C6-C12) in milk were derived from glucose but increased to 75 and 25% with feeding. Expression of genes involved in FA or glycerol synthesis was unchanged regardless of diet or fast/fed conditions. The human MG is capable of de novo lipogenesis of primarily MCFA and glycerol, which is influenced by the macronutrient composition of the maternal diet.
RCT Entities:
UNLABELLED: Mammary gland (MG) de novo lipogenesis contributes significantly to milk fat in animals but little is known in humans. OBJECTIVE: To test the hypothesis that the incorporation of (13)C carbons from [U-(13)C]glucose into fatty acids (FA) and glycerol in triglycerides (TG) will be greater: 1) in milk than plasma TG, 2) during a high-carbohydrate (H-CHO) diet than high-fat (H-FAT) diet, and 3) during feeding than fasting. Seven healthy, lactating women were studied on two isocaloric, isonitrogenous diets. On one occasion, subjects received diets containing H-FAT or H-CHO diet for 1 wk. Incorporation of (13)C from infused [U-(13)C]glucose into FA and glycerol was measured using GC-MS and gene expression in RNA isolated from milk fat globule using microarrays. Incorporation of (13)C2 into milk FA increased with increased FA chain length from C2:0 to C12:0 but progressively declined in C14:0 and C16:0 and was not detected in FA>C16. During feeding, regardless of diets, enrichment of (13)C2 in milk FA and (13)C3 in milk glycerol were ∼ 3- and ∼ 7-fold higher compared with plasma FA and glycerol, respectively. Following an overnight fast during H-CHO and H-FAT diets, 25 and 6%, respectively, of medium-chain FA (MCFA, C6-C12) in milk were derived from glucose but increased to 75 and 25% with feeding. Expression of genes involved in FA or glycerol synthesis was unchanged regardless of diet or fast/fed conditions. The human MG is capable of de novo lipogenesis of primarily MCFA and glycerol, which is influenced by the macronutrient composition of the maternal diet.
Authors: Lee Call; Tiffany Molina; Barbara Stoll; Greg Guthrie; Shaji Chacko; Jogchum Plat; Jason Robinson; Sen Lin; Caitlin Vonderohe; Mahmoud Mohammad; Dennis Kunichoff; Stephanie Cruz; Patricio Lau; Muralidhar Premkumar; Jon Nielsen; Zhengfeng Fang; Oluyinka Olutoye; Thomas Thymann; Robert Britton; Per Sangild; Douglas Burrin Journal: J Lipid Res Date: 2020-04-29 Impact factor: 5.922
Authors: Melinda A Engevik; Heather A Danhof; Ritu Shrestha; Alexandra L Chang-Graham; Joseph M Hyser; Anthony M Haag; Mahmoud A Mohammad; Robert A Britton; James Versalovic; Joseph A Sorg; Jennifer K Spinler Journal: Gut Microbes Date: 2020-11-09