The role of intestinal bifidobacteria on immune system development in young rats

Early Hum Dev. 2010 Jan;86(1):51-8. doi: 10.1016/j.earlhumdev.2010.01.002. Epub 2010 Jan 27.

Abstract

Aim: The effects of intestinal bifidobacteria on the development of immunity in early life were explored.

Methods: Neonatal SD rats born and housed under strict barrier systems were fed from birth with sufficient antibiotics (bifidobacteria minimisation group) or supplemented daily with 1x10(10) colony-forming units of live Bifidobacterium longum (bifidobacteria supplementation group). Relevant indices of immune development were determined at one, three and six weeks old.

Results: Compared to the control group, minimisation of the intestinal bifidobacteria delayed maturation of dendritic cells in Peyer's Patches and the development of T cells in the thymus, increased IL-4 secretion in the plasma, down-regulated IL-12, IL-10 mRNA and the interferon-gamma/IL-4 mRNA ratio in intestinal mucosa, decreased interferon-gamma mRNA in cultured peripheral blood mononuclear cells (PBMCs), and reduced immunoglobulin-M production in cultured PBMCs. Conversely, supplementation with bifidobacteria promoted dendritic cell maturation in Peyer's Patches, up-regulated IL-12, IL-10, interferon-gamma mRNA and the interferon-gamma/IL-4 ratio in intestinal mucosa, increased interferon-gamma gene expression in cultured PBMCs, and raised immunoglobulin-M secretion in cultured PBMCs.

Conclusions: Intestinal bifidobacteria could promote the maturation of dendritic cells and its expression of IL-12 locally in the gut, influence the development of T cells in the thymus, favour the development of T-helper cell type 1 response by increasing the local and systemic expression of interferon-gamma and ensure the intestinal regulatory T cell response by promoting the local expression of IL-10. In addition, they enhance antibody synthesis by PBMCs, thereby affecting the development of both the gut and systemic immunity in early life.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Analysis of Variance
  • Animals
  • Animals, Newborn
  • Bifidobacterium / immunology*
  • Enzyme-Linked Immunosorbent Assay
  • Immune System / growth & development*
  • Immune System / microbiology*
  • Interleukin-1 / immunology
  • Interleukin-4 / immunology
  • Intestines / immunology
  • Intestines / microbiology*
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / microbiology
  • Lymphocyte Activation / immunology
  • Peyer's Patches / immunology
  • Peyer's Patches / microbiology
  • Rats
  • Rats, Sprague-Dawley
  • Reverse Transcriptase Polymerase Chain Reaction
  • T-Lymphocytes / immunology
  • T-Lymphocytes / microbiology
  • Thymus Gland / immunology
  • Thymus Gland / microbiology

Substances

  • Interleukin-1
  • Interleukin-4