title: The Microbiome, Intestinal Function, and Arginine Metabolism of Healthy Indian Women Are Different from Those of American and Jamaican Women.
abstract: BACKGROUND
  Indian women have slower arginine flux during pregnancy compared with American and Jamaican women. Arginine is a semi-essential amino acid that becomes essential during periods of rapid lean tissue deposition. It is synthesized only from citrulline, a nondietary amino acid produced mainly in the gut. The gut is therefore a key site of arginine and citrulline metabolism, and gut microbiota may affect their metabolism.
  
  
  OBJECTIVE
  The objective of this study was to identify differences in the gut microbiota of nonpregnant American, Indian, and Jamaican women and characterize the relations between the gut microbiota, gut function, and citrulline and arginine metabolism.
  
  
  METHODS
  Thirty healthy American, Indian, and Jamaican women (n = 10/group), aged 28.3 ± 0.8 y, were infused intravenously with [guanidino-15N2]arginine, [5,5-2H2]citrulline, and [15N2]ornithine and given oral [U-13C6]arginine in the fasting and postprandial states. Fecal bacterial communities were characterized by 16S rRNA gene sequencing.
  
  
  RESULTS
  In the fasting state, Indian women had lower citrulline flux than did American and Jamaican women [7.0 ± 0.4 compared with 9.1 ± 0.4 and 8.9 ± 0.2 μmol ⋅ kg fat-free mass (FFM)-1 ⋅ h-1, P = 0.01] and greater enteral arginine conversion to ornithine than did American women (1.4 ± 0.11 compared with 1.0 ± 0.08 μmol ⋅ kg FFM-1 ⋅ h-1, P = 0.04). They also had lower mannitol excretion than American and Jamaican women (154 ± 37.1 compared with 372 ± 51.8 and 410 ± 39.6 mg/6 h, P < 0.01). Three dominant stool community types characterized by increased abundances of the genera Prevotella, Bacteroides, and Bacteroides with Clostridium were identified. Indian women had increased mean relative abundances of Prevotella (42%) compared to American and Jamaican women (7% and < 1%, P = 0.03) which were associated with diet, impaired intestinal absorptive capacity, and arginine flux.
  
  
  CONCLUSIONS
  These findings suggest that dysregulated intestinal function and a unique gut microbiome may contribute to altered arginine metabolism in Indian women.
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.|Section of Pulmonary, Critical Care, and Sleep, Department of Medicine, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.
authors.forename: Christina C
authors.initials: CC
authors.lastname: Kao
authors.affiliation: Department of Pathology and Immunology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.|Texas Children's Microbiome Center, Department of Pathology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.
authors.forename: Julia L
authors.initials: JL
authors.lastname: Cope
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.
authors.forename: Jean W
authors.initials: JW
authors.lastname: Hsu
authors.affiliation: St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India.
authors.forename: Pratibha
authors.initials: P
authors.lastname: Dwarkanath
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Karnes
authors.affiliation: Department of Pathology and Immunology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.|Texas Children's Microbiome Center, Department of Pathology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Luna
authors.affiliation: Department of Pathology and Immunology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.|Texas Children's Microbiome Center, Department of Pathology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.
authors.forename: Emily B
authors.initials: EB
authors.lastname: Hollister
authors.affiliation: Department of Child and Adolescent Health, University of West Indies, Mona, Kingston, Jamaica.
authors.forename: Minerva M
authors.initials: MM
authors.lastname: Thame
authors.affiliation: St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India.
authors.forename: Anura V
authors.initials: AV
authors.lastname: Kurpad
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX.
authors.forename: Farook
authors.initials: F
authors.lastname: Jahoor
keywords: arginine; citrulline; intestinal permeability; microbiome; nonpregnant women