title: Intestinal parasites increase the dietary lysine requirement in chronically undernourished Indian men.
abstract: BACKGROUND
  We previously used the 24-h indicator amino acid balance method to show that the lysine requirement in undernourished Indian men from low socioeconomic and unsanitary environments is approximately 50% higher than the mean requirement of 30 mg lysine. kg(-1). d(-1) in well-nourished men.
  
  
  OBJECTIVE
  It is possible that this higher lysine requirement in persons with chronic undernutrition is due to environmental influences, including the presence of intestinal parasites. We assessed this possibility by using 24-h indicator amino acid balance (with leucine) at both the "normal" requirement for lysine intake and the higher requirement, before and after successful treatment to eradicate intestinal parasites in affected, undernourished men.
  
  
  METHODS
  Fourteen chronically undernourished men were studied before and after treatment for intestinal parasites, during each of two 7-d (6-d dietary adaptation plus 1-d tracer experiment) diet periods supplying either 30 (n = 7) or 45 (n = 7) mg lysine. kg(-1). d(-1) from an L-amino acid diet. Twenty-four-hour indicator amino acid balance was estimated on day 6 by [(13)C]leucine tracer infusion.
  
  
  RESULTS
  Before the parasite treatment, subjects were in neutral 24-h leucine balance at both lysine intakes. After the eradication of intestinal parasites, there was a significant (P < 0.001) improvement in 24-h leucine balances, which were positive at both lysine intakes.
  
  
  CONCLUSIONS
  On the basis of the 24-h indicator amino acid balance approach, it appears that intestinal infestation with parasites increases the requirement for lysine and that this may be one factor responsible for the higher lysine requirement observed in persons with chronic undernutrition.
authors.affiliation: Department of Physiology and the Division of Nutrition, St John's Medical College, Bangalore, India.
authors.forename: Anura V
authors.initials: AV
authors.lastname: Kurpad
authors.forename: Meredith M
authors.initials: MM
authors.lastname: Regan
authors.forename: Dilip
authors.initials: D
authors.lastname: Nazareth
authors.forename: Savita
authors.initials: S
authors.lastname: Nagaraj
authors.forename: Justin
authors.initials: J
authors.lastname: Gnanou
authors.forename: Vernon R
authors.initials: VR
authors.lastname: Young
mesh_terms: D000328:Adult; D000886:Anthropometry; D002247:Carbon Isotopes; D002908:Chronic Disease; D005243:Feces / Q000469:parasitology; D006801:Humans; D007194:India / Q000453:epidemiology; D007411:Intestinal Diseases, Parasitic / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology*; D008239:Lysine / Q000008:administration & dosage* / Q000378:metabolism*; D008297:Male; D044342:Malnutrition / Q000209:etiology* / Q000469:parasitology; D009751:Nutritional Requirements; D009752:Nutritional Status
chemical_list: D002247:Carbon Isotopes; D008239:Lysine