title: Reversal of parenteral nutrition-induced gut mucosal immunity impairment with small amounts of a complex enteral diet.
abstract: BACKGROUND
  Although parenteral nutrition (PN) prevents progressive malnutrition, lack of enteral nutrition (EN) during PN leads to gut associated lymphoid tissue (GALT) atrophy and dysfunction. Administering a small amount of EN with PN reportedly prevents increases in intestinal permeability. However, its effects on GALT remain unclear. We analyzed the minimum amount of EN required to preserve gut immunity during PN.
  
  
  METHODS
  Male Institute of Cancer Research mice underwent jugular vein catheter insertion and tube gastrostomy. They were randomized into four groups to receive isocaloric and isonitrogenous nutritional support with variable EN to PN ratios (EN 0, EN 33, EN 66, and EN 100). EN was provided with a complex enteral diet. After 5 days of feeding, the mice were killed and whole small intestines were harvested. GALT lymphocytes were isolated and counted. Their phenotypes were analyzed by flow cytometry. IgA levels of small intestinal washings were analyzed with enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Body weight changes did not differ between any two of the groups. Peyer's patch lymphocyte numbers increased in proportion to EN amount, whereas lamina propria lymphocyte numbers were significantly higher in the EN 100 than in the EN 0 group, with no marked increases in the EN 33 and EN 66 groups. Small intestinal IgA levels increased EN amount-dependently and reached a plateau at EN 66.
  
  
  CONCLUSIONS
  A small amount of EN partially reverses PN-induced GALT changes, suggesting beneficial but limited effects on gut mucosal immunity.
authors.affiliation: Division of Traumatology, National Defense Medical College Research Institute, Saitama, Japan.
authors.forename: Fumie
authors.initials: F
authors.lastname: Ikezawa
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Fukatsu
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Moriya
authors.forename: Chikara
authors.initials: C
authors.lastname: Ueno
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Maeshima
authors.forename: Koichi
authors.initials: K
authors.lastname: Okamoto
authors.forename: Etsuko
authors.initials: E
authors.lastname: Hara
authors.forename: Daizoh
authors.initials: D
authors.lastname: Saitoh
mesh_terms: D000818:Animals; D004750:Enteral Nutrition; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D018928:Immunity, Mucosal / Q000502:physiology*; D007070:Immunoglobulin A / Q000032:analysis; D007413:Intestinal Mucosa / Q000276:immunology*; D018655:Lymphocyte Count; D008221:Lymphoid Tissue / Q000276:immunology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009092:Mucous Membrane / Q000166:cytology; D010288:Parenteral Nutrition / Q000009:adverse effects*; D010581:Peyer's Patches / Q000166:cytology
chemical_list: D007070:Immunoglobulin A