title: Some putative prebiotics increase the severity of Salmonella enterica serovar Typhimurium infection in mice.
abstract: BACKGROUND
  Prebiotics are non-digestible food ingredients believed to beneficially affect host health by selectively stimulating the growth of the beneficial bacteria residing in the gut. Such beneficial bacteria have been reported to protect against pathogenic infections. However, contradicting results on prevention of Salmonella infections with prebiotics have been published. The aim of the present study was to examine whether S. Typhimurium SL1344 infection in mice could be prevented by administration of dietary carbohydrates with different structures and digestibility profiles. BALB/c mice were fed a diet containing 10% of either of the following carbohydrates: inulin, fructo-oligosaccharide, xylo-oligosaccharide, galacto-oligosaccharide, apple pectin, polydextrose or beta-glucan for three weeks prior to oral Salmonella challenge (107 CFU) and compared to mice fed a cornstarch-based control diet.
  
  
  RESULTS
  The mice fed with diets containing fructo-oligosaccharide (FOS) or xylo-oligosaccharide (XOS) had significantly higher (P < 0.01 and P < 0.05) numbers of S. Typhimurium SL1344 in liver, spleen and mesenteric lymph nodes when compared to the mice fed with the cornstarch-based control diet. Significantly increased amounts (P < 0.01) of Salmonella were detected in ileal and fecal contents of mice fed with diets supplemented with apple pectin, however these mice did not show significantly higher numbers of S. Typhimyrium in liver, spleen and lymph nodes than animals from the control group (P < 0.20).The acute-phase protein haptoglobin was a good marker for translocation of S. Typhimurium in mice. In accordance with the increased counts of Salmonella in the organs, serum concentrations of haptoglobin were significantly increased in the mice fed with FOS or XOS (P < 0.001). Caecum weight was increased in the mice fed with FOS (P < 0.01), XOS (P < 0.01), or polydextrose (P < 0.001), and caecal pH was reduced in the mice fed with polydextrose (P < 0.001). In vitro fermentation in monocultures revealed that S. Typhimurium SL1344 is capable of fermenting FOS, beta-glucan and GOS with a corresponding decline in pH.
  
  
  CONCLUSIONS
  Supplementing a cornstarch-based rodent diet with 10% FOS or XOS was found to increase the translocation of S. Typhimurium SL1344 to internal organs in mice, while 10% apple pectin was found to increase the numbers of S. Typhimurium in intestinal content and feces.
authors: The National Food Institute, Department of Microbiology and Risk Assessment, Technical University of Denmark, Moerkhoej Bygade 19, DK-2860 Soeborg, Denmark. apet@food.dtu.dk
authors: Anne
authors: A
authors: Petersen
authors: Peter M H
authors: PM
authors: Heegaard
authors: Anna L
authors: AL
authors: Pedersen
authors: Jens B
authors: JB
authors: Andersen
authors: Rikke B
authors: RB
authors: Sørensen
authors: Hanne
authors: H
authors: Frøkiaer
authors: Sampo J
authors: SJ
authors: Lahtinen
authors: Arthur C
authors: AC
authors: Ouwehand
authors: Morten
authors: M
authors: Poulsen
authors: Tine R
authors: TR
authors: Licht
mesh_terms: D000818:Animals; D001835:Body Weight / Q000502:physiology; D002432:Cecum / Q000502:physiology; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D005243:Feces / Q000382:microbiology; D005285:Fermentation / Q000502:physiology; D006242:Haptoglobins / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008807:Mice, Inbred BALB C; D056692:Prebiotics; D012480:Salmonella Infections / Q000382:microbiology / Q000503:physiopathology*; D012486:Salmonella typhimurium / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D013154:Spleen / Q000166:cytology
chemical_list: D004040:Dietary Carbohydrates; D006242:Haptoglobins; D056692:Prebiotics