Monocolonization with Bacteroides ovatus protects immunodeficient SCID mice from mortality in chronic intestinal inflammation caused by long-lasting dextran sodium sulfate treatment

Physiol Res. 2009;58(1):101-110. doi: 10.33549/physiolres.931340. Epub 2008 Jan 17.


This study was aimed to evaluate the role of commensal Gram-negative bacterium Bacteroides ovatus in murine model of chronic intestinal inflammation. The attempt to induce chronic colitis was done in Bacteroides ovatus-monoassociated, germ-free and conventional mice either in immunocompetent (BALB/c) mice or in mice with severe combined immunodeficiency (SCID), using 2.5 % dextran-sodium sulfate (DSS) in drinking water (7 days DSS, 7 days water, 7 days DSS). Conventional mice developed chronic colitis. Some of germ-free BALB/c and the majority of germ-free SCID mice did not survive the long-term treatment with DSS due to massive bleeding into the intestinal lumen. However, monocolonization of germ-free mice of both strains with Bacteroides ovatus prior to long-term treatment with DSS protected mice from bleeding, development of intestinal inflammation and precocious death. We observed that though DSS-treated Bacteroides ovatus-colonized SCID mice showed minor morphological changes in colon tissue, jejunal brush-border enzyme activities such as gamma-glutamyltranspeptidase, lactase and alkaline phosphatase were significantly reduced in comparison with DSS-untreated Bacteroides ovatus-colonized mice. This modulation of the enterocyte gamma-glutamyltranspeptidase localized to the brush border membrane has been described for the first time. This enzyme is known to reflect an imbalance between pro-oxidant and anti-oxidant mechanisms, which could be involved in protective effects of colonization of germ-free mice with Bacteroides ovatus against DSS injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / metabolism
  • Animals
  • Bacteroides / growth & development*
  • Chronic Disease
  • Colitis / chemically induced
  • Colitis / enzymology
  • Colitis / microbiology
  • Colitis / pathology
  • Colitis / prevention & control*
  • Colon / microbiology*
  • Colon / pathology
  • Dextran Sulfate
  • Disease Models, Animal
  • Intestinal Mucosa / enzymology
  • Jejunum / enzymology
  • Lactase / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Mice, SCID
  • Microvilli / enzymology
  • Severity of Illness Index
  • Time Factors
  • gamma-Glutamyltransferase / metabolism


  • Dextran Sulfate
  • gamma-Glutamyltransferase
  • Alkaline Phosphatase
  • Lactase