title: Probiotic Lactobacillus rhamnosus GG modulates the mucosal immune response in Giardia intestinalis-infected BALB/c mice.
abstract: BACKGROUND
  Gut homeostasis can be altered by the oral administration of health-promoting microorganisms, namely probiotics that are known to reinforce the host immune response.
  
  
  OBJECTIVE
  The aim of this study was to elucidate the immunomodulatory effect of orally administered probiotic Lactobacillus rhamnosus GG (LGG) in Giardia-infected mice.
  
  
  METHODS
  BALB/c mice were fed orally with probiotic LGG either 7 days prior to or simultaneously with the challenge dose of Giardia trophozoites. The administration of the probiotic was continued for 25 days, and immunomodulatory potentials in terms of secretory immunoglobulin A (IgA) levels, CD8+ and CD4+ T lymphocytes, and expression of pro-inflammatory [tumor necrosis factor-alpha, interferon-gamma (INF-γ)] and anti-inflammatory cytokines [interleukin (IL)-4, IL-6, IL-10] were studied.
  
  
  RESULTS
  Oral feeding of LGG prior to or simultaneously with the test dose of Giardia seems to have modulated both arms (humoral and cellular) of the mucosal immune system since a significant increase in the levels of specific secretory IgA antibody, IgA+ cells, and CD4+ T lymphocytes were observed in contrast with the decreased percentage of cytotoxic CD8+ T lymphocytes. The stimulated mucosal immune response in probiotic fed Giardia-infected mice was further correlated with the enhanced levels of anti-inflammatory cytokines IL-6 and IL-10 and reduced levels of pro-inflammatory cytokine INF-γ.
  
  
  CONCLUSIONS
  This is the first study to show that oral administration of the effective probiotic LGG to Giardia infected mice could be used as a bacterio-therapy that restores the normal gut microflora and modulates the mucosal immune response.
authors.affiliation: Department of Microbiology, Panjab University, Chandigarh, 160014, India.
authors.forename: Nisha
authors.initials: N
authors.lastname: Goyal
authors.forename: Geeta
authors.initials: G
authors.lastname: Shukla
mesh_terms: D000284:Administration, Oral; D000818:Animals; D018791:CD4 Lymphocyte Count; D016207:Cytokines / Q000378:metabolism; D005260:Female; D016829:Giardia lamblia / Q000302:isolation & purification; D005873:Giardiasis / Q000276:immunology / Q000378:metabolism / Q000628:therapy*; D007070:Immunoglobulin A / Q000378:metabolism; D056747:Immunomodulation; D007413:Intestinal Mucosa / Q000276:immunology*; D052201:Lacticaseibacillus rhamnosus; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D019936:Probiotics / Q000627:therapeutic use*
chemical_list: D016207:Cytokines; D007070:Immunoglobulin A