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Updated: Jun 18, 2026
Probiotic Studies in Neonatal Mice Using Gavage
Published on: January 27, 2019
Probiotics prevent death caused by Citrobacter rodentium infection in neonatal mice
Mélanie G Gareau1, Eytan Wine, Colin Reardon
1Cell Biology Program, Research Institute, Hospital for Sick Children, University of Toronto, Ontario, Canada.
Insights
Probiotics promote survival in neonatal mice infected with Citrobacter rodentium, but only when T cells are present. This study highlights the importance of T cell immunity in mitigating severe enteric infections.
Area of Science:
- Microbiology
- Immunology
- Neonatal Health
Background:
- Intestinal bacterial infections pose significant risks to neonates, causing substantial morbidity and mortality.
- Citrobacter rodentium is a common enteric pathogen studied in mouse models of infection.
Purpose of the Study:
- To characterize Citrobacter rodentium infection in neonatal mice.
- To investigate the protective role of specific probiotics against C. rodentium-induced disease.
Main Methods:
- Neonatal C57BL/6 mice were infected with C. rodentium at postnatal day 14.
- Mice received oral probiotics (Lactobacillus rhamnosus and Lactobacillus helveticus) or placebo prior to infection.
- Immunodeficient mice (rag1(-/-) and JH(-/-)) were used to assess the roles of T and B cells.
Main Results:
- C. rodentium infection led to weight loss and mortality in neonatal mice.
- Probiotic treatment significantly improved survival and ameliorated disease symptoms, including weight loss and colonic damage.
- Probiotic benefits were dependent on the presence of T cells, as immunodeficient rag1(-/-) mice did not show improved outcomes.
Conclusions:
- Neonatal Citrobacter rodentium infection is lethal in mice.
- Probiotics enhance survival and reduce disease severity in C. rodentium-infected neonatal mice.
- The protective effects of probiotics are mediated through T cell-dependent mechanisms.
Background:
Intestinal bacterial infections are a major cause of morbidity and mortality, especially in neonates. Therefore, the aims of this study were to characterize Citrobacter rodentium infection in neonatal mice and determine the role played by specific probiotics in ameliorating disease severity.
Methods:
Infection of C57BL/6 mice with C. rodentium was performed at postnatal day 14. A subset of mice was pretreated orally with either a mixture of Lactobacillus rhamnosus and Lactobacillus helveticus or placebo, starting at 7 days. To study the effects of B and T cells, rag1(-/-) and JH(-/-) mice were used, with survival, colonic crypt depth, and barrier function evaluated as outcome measures.
Results:
C. rodentium infection caused weight loss and death. In contrast, survival was maintained by daily treatment with Lactobacilli. Weight loss, colonic epithelial cell hyperplasia, mucosal barrier dysfunction, and elevated serum corticosterone levels in C. rodentium-infected wild-type mice were ameliorated by probiotics, but not in rag1(-/-) animals. Beneficial effects of probiotics were observed in B cell-deficient (JH(-/-)) mice, indicating the requirement of T cells in reducing the adverse sequelae of neonatal enteric infection.
Conclusions:
These findings demonstrate that C. rodentium infection in newborn mice causes death and that probiotics promote survival, but only in the presence of T cells.
