Effects of three major amino acids found in Japanese broth on glucose metabolism and gastric emptying

• Published in: Nutrition (Burbank, Los Angeles County, Calif.) Los Angeles County, Calif.), 2018-02, Vol.46, p.153-158.e1
• Main Authors: Mano, Fumika, Ikeda, Kaori, Joo, Erina, Yamane, Shunsuke, Harada, Norio, Inagaki, Nobuya
• Format: Article
• Language: English
• Subjects: Acetic acid; Adult; Alcohol; Amino acids; Amino Acids - administration & dosage; Animals; Aspartic Acid - administration & dosage; Aspartic Acid - analysis; Blood Glucose - drug effects; Blood Glucose - metabolism; Broths; C-Peptide - blood; Cooking stock; Cross-Over Studies; Diabetes; Diet; Digestion; Emptying; Female; Fishes; Food, Preserved - analysis; Functional dyspepsia; Gastric emptying; Gastric Emptying - drug effects; Gastric motility; Gastroenterology; GIP protein; Glucagon; Glucagon - blood; Glucagon-like peptide 1; Glucagon-Like Peptide 1 - blood; Glucose; Glucose metabolism; Glutamic Acid - administration & dosage; Glutamic Acid - analysis; Helicobacter pylori; Histidine; Histidine - administration & dosage; Histidine - analysis; Hot water; Humans; Ingestion; Insulin; Insulin - blood; Japan; Japanese diet; Kelp - chemistry; Male; Meals; Metabolism; Monosodium l-glutamate; Oryza; Polypeptides; Restaurants; Rice; Rodents; Secretion; Sodium; Sodium acetate; Sodium chloride; Soup; Synthesis
• ISSN: 0899-9007; 1873-1244
• DOI: 10.1016/j.nut.2017.08.007

To our knowledge, the effect of the broth of dried kelp and dried bonito, dashi, on glucose metabolism and digestion has rarely been studied. Based on the component analysis of three actual broths served in traditional restaurants, a chemically synthesized broth with three free amino acids (histidine, glutamate, aspartate) and salt was prepared to investigate their effect on glucose metabolism, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide 1 (GLP-1) secretion, and digestion. In study 1, seven healthy individuals were enrolled in a four-period crossover study. Participants drank or ate hot water, synthesized broth, hot water with rice, and synthesized broth with rice. Plasma glucose, serum insulin, plasma glucagon, plasma GIP, and plasma GLP-1 were measured at baseline and after ingestion. In study 2, 6 of the 7 individuals ingested rice steamed with 13C-labeled sodium acetate with hot water or synthesized broth to estimate gastric emptying by the 13C-labeled acetate breath test in a two-period crossover trial. Ingesting water or synthesized broth alone elicited no change in plasma glucose or serum insulin levels. Ingesting synthesized broth with rice resulted in a rapid rise in plasma glucose and GLP-1 (P = 0.01 and 0.02, respectively) in an early postprandial phase compared with that by ingesting water with rice, but the area under the curve of those showed no significant differences. Ingesting synthesized broth with rice resulted in a significantly higher gastric emptying coefficient than that after rice with water (P = 0.03). Three amino acids and sodium chloride corresponding to those found in actual broth promoted gastric emptying and led to a rapid response of plasma glucose. Our findings suggest that ingestion of the broth of dried kelp and dried bonito may improve gastric motility. •Three amino acids were identified as major components of traditional Japanese broth.•Readily reproducible broth was synthesized from the three amino acids and salt.•The three amino acids and salt parallel to real broth promoted gastric emptying.