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Updated: May 25, 2026
A Neonatal BALB/c Mouse Model of Necrotizing Enterocolitis
Published on: November 30, 2021
Bifidobacterium bifidum in a rat model of necrotizing enterocolitis: antimicrobial peptide and protein responses
Mark A Underwood1, Anchasa Kananurak, Christine F Coursodon
1Department of Pediatrics, University of California-Davis, Sacramento, California, USA. mark.underwood@ucdmc.ucdavis.edu
Insights
Probiotics like Bifidobacterium bifidum reduce the risk of necrotizing enterocolitis (NEC) in premature infants by modulating antimicrobial peptide expression. This study shows probiotics help prevent NEC by regulating these gut peptides.
Area of Science:
- Gastroenterology
- Neonatology
- Microbiology
Background:
- Necrotizing enterocolitis (NEC) is a severe intestinal disease affecting premature infants.
- Probiotics are known to reduce NEC risk, but their effect on antimicrobial peptides in NEC is not well understood.
Purpose of the Study:
- To examine antimicrobial peptide expression in experimental NEC.
- To determine how probiotics influence antimicrobial peptide levels in NEC.
Main Methods:
- Premature rats were divided into dam-fed, formula-fed, and formula-fed with Bifidobacterium bifidum groups.
- All groups were subjected to asphyxia and cold stress to induce NEC-like conditions.
- Antimicrobial peptide gene expression was analyzed in the different experimental groups.
Main Results:
- Antimicrobial peptide expression was significantly elevated in formula-fed rats with NEC compared to controls.
- Probiotic supplementation with Bifidobacterium bifidum attenuated NEC and reduced the elevated antimicrobial peptide levels.
- Antimicrobial peptide expression in rat pups mirrored patterns seen in human development, increasing with age.
Conclusions:
- Antimicrobial peptide induction is a response to experimental NEC, similar to human disease.
- Probiotic B. bifidum mitigates experimental NEC and normalizes antimicrobial peptide expression.
- While an adaptive response, antimicrobial peptides alone may not be sufficient to prevent NEC in the vulnerable premature gut.
Introduction:
Necrotizing enterocolitis (NEC) is a devastating disease of premature infants. Probiotics decrease the risk of NEC in clinical and experimental studies. Antimicrobial peptides protect the gut against noxious microbes and shape the commensal microbiota, but their role in NEC remains unclear.
Methods:
To investigate the expression of antimicrobial peptides in experimental NEC and the impact of probiotics on their expression, premature rats were divided into three groups: dam fed (DF), hand fed with formula (FF), or hand fed with formula containing Bifidobacterium bifidum (FF + BIF). All groups were exposed to asphyxia and cold stress.
Results:
Like in human ontogeny, the rat pup has low expression of Paneth cell antimicrobials, which increases rapidly during normal development. The expression of lysozyme, secretory phospholipase A(2) (sPLA(2)), pancreatic-associated proteins 1 and 3 mRNA was elevated in the FF group with a high incidence of NEC, as compared with the DF and FF + BIF groups where the disease was attenuated.
Discussion:
We conclude that induction of antimicrobial peptides occurs in experimental NEC similar to that reported in human disease and is attenuated when disease is averted by probiotic B. bifidum. The induction of antimicrobial peptides is likely an adaptive mucosal response that is often not sufficient to prevent disease in the premature gut.
