title: Jejunal Casein Feeding Is Followed by More Rapid Protein Digestion and Amino Acid Absorption When Compared with Gastric Feeding in Healthy Young Men.
abstract: BACKGROUND
  Dietary protein is required to attenuate the loss of muscle mass and to support recovery during a period of hospitalization. Jejunal feeding is preferred over gastric feeding in patients who are intolerant of gastric feeding. However, the impact of gastric vs. jejunal feeding on postprandial dietary protein digestion and absorption kinetics in vivo in humans remains largely unexplored.
  
  
  OBJECTIVE
  We compared the impact of gastric vs. jejunal feeding on subsequent dietary protein digestion and amino acid (AA) absorption in vivo in healthy young men.
  
  
  METHODS
  In a randomized crossover study design, 11 healthy young men (aged 21 ± 2 y) were administered 25 g specifically produced intrinsically l-[1-(13)C]phenylalanine-labeled intact casein via a nasogastric and a nasojejunal tube placed ~30 cm distal to the ligament of Treitz. Protein was provided in a 240-mL solution administered over a 65-min period in both feeding regimens. Blood samples were collected during the 7-h postprandial period to assess the increase in plasma AA concentrations and dietary protein-derived plasma l-[1-(13)C]phenylalanine enrichment.
  
  
  RESULTS
  Jejunal feeding compared with gastric feeding resulted in higher peak plasma phenylalanine, leucine, total essential AA (EAA), and total AA concentrations (all P < 0.05). This was attributed to a more rapid release of dietary protein-derived AAs into the circulation, as evidenced by a higher peak plasma l-[1-(13)C]phenylalanine enrichment concentration (2.9 ± 0.2 vs. 2.2 ± 0.2 mole percent excess; P < 0.05). The total postprandial plasma AA incremental area under the curve and time to peak did not differ after jejunal vs. gastric feeding. Plasma insulin concentrations increased to a greater extent after jejunal feeding when compared with gastric feeding (275 ± 38 vs. 178 ± 38 pmol/L; P < 0.05).
  
  
  CONCLUSIONS
  Jejunal feeding of intact casein is followed by more rapid protein digestion and AA absorption when compared with gastric feeding in healthy young men. The greater postprandial increase in circulating EAA concentrations may allow a more robust increase in muscle protein synthesis rate after jejunal vs. gastric casein feeding. This trial was registered at trialregister.nl as NTR2801.
authors.affiliation: Departments of Surgery and Nutricia Research, Utrecht, Netherlands; j.luttikhold@vumc.nl.
authors.forename: Joanna
authors.initials: J
authors.lastname: Luttikhold
authors.affiliation: Nutrition and Pharmacology Group, Division of Human Nutrition, Wageningen University, Wageningen, Netherlands;
authors.forename: Klaske
authors.initials: K
authors.lastname: van Norren
authors.affiliation: Departments of Surgery and.
authors.forename: Nikki
authors.initials: N
authors.lastname: Buijs
authors.affiliation: Departments of Surgery and.
authors.forename: Marjolein
authors.initials: M
authors.lastname: Ankersmit
authors.affiliation: Clinical Chemistry, VU University Medical Center, Amsterdam, Netherlands;
authors.forename: Annemieke C
authors.initials: AC
authors.lastname: Heijboer
authors.affiliation: ATAL-Medial Diagnostische Centra, Hoofddorp, Netherlands;
authors.forename: Jeannette
authors.initials: J
authors.lastname: Gootjes
authors.affiliation: Department of Surgery, Spaarne Gasthuis, Haarlem, Netherlands; and.
authors.forename: Herman
authors.initials: H
authors.lastname: Rijna
authors.affiliation: Departments of Surgery and.
authors.forename: Paul A M
authors.initials: PA
authors.lastname: van Leeuwen
authors.affiliation: NUTRIM School for Nutrition, Toxicology, and Metabolism, Maastricht University, Maastricht, Netherlands.
authors.forename: Luc J C
authors.initials: LJ
authors.lastname: van Loon
mesh_terms: D000293:Adolescent; D000328:Adult; D000596:Amino Acids / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D002247:Carbon Isotopes; D002364:Caseins / Q000008:administration & dosage* / Q000493:pharmacokinetics; D018592:Cross-Over Studies; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage; D004750:Enteral Nutrition / Q000379:methods*; D065569:Gastrointestinal Absorption / Q000187:drug effects*; D006801:Humans; D007328:Insulin / Q000097:blood; D007408:Intestinal Absorption / Q000187:drug effects*; D007583:Jejunum / Q000187:drug effects* / Q000378:metabolism; D007930:Leucine / Q000097:blood; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009124:Muscle Proteins / Q000378:metabolism; D010649:Phenylalanine / Q000097:blood; D019518:Postprandial Period / Q000187:drug effects; D059748:Proteolysis; D055815:Young Adult
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D002247:Carbon Isotopes; D002364:Caseins; D004044:Dietary Proteins; D007328:Insulin; D009124:Muscle Proteins; D010649:Phenylalanine; D007930:Leucine
keywords: casein; enteral nutrition; gastric feeding; jejunal feeding; malnutrition; protein