Gastrointestinal Infection Models for Preclinical Research

Gastrointestinal (GI) infections represent a critical global health burden. They are a major cause of morbidity and mortality, particularly among children, elderly individuals, and immunocompromised patients. The increasing prevalence of antimicrobial resistance, recurrent hospital-acquired GI infections, and limited therapeutic options highlight the urgent need for innovative approaches.

At Vibiosphen, we provide robust and translational gastrointestinal infection models in rodents to support the development of novel antibiotics, probiotics, antifungals, microbiome-based therapies, and vaccines. Our models are designed to generate clinically relevant data that help pharmaceutical and biotechnology companies accelerate drug discovery and translational research.
 

Background of Gastrointestinal Infections

Gastrointestinal infections are caused by diverse bacterial and fungal pathogens and present with outcomes ranging from acute diarrhea to life-threatening colitis and systemic complications. Their burden is amplified by:

• The rise of multidrug-resistant enteric bacteria
• The high recurrence rate of Clostridioides difficile infections
• The role of dysbiosis in infection susceptibility and relapse
• The limited availability of antifungal options for GI infections

Preclinical gastrointestinal infection models are therefore essential for evaluating the efficacy, safety, and mechanism of action of new therapeutic candidates before progressing further in drug development.
 

Rodent Models of Gastrointestinal Infections

Mouse lineages

• The primary mouse lineages used in preclinical studies are inbred strains known for their genetic uniformity, which minimizes experimental variability.
  • C57BL/6 mice have a T-helper type 1 (Th1) biased immune response, which is a cellular immune response important for fighting intracellular pathogens.
  • BALB/c mice have a T-helper type 2 (Th2) biased immune response. A Th2 response is a humoral immune response that relies on antibodies and is essential for combatting extracellular parasites.

• Outbred mice, unlike their inbred counterparts, are maintained in large, randomly bred colonies to maximize genetic variation. This heterogeneity makes each mouse genetically unique.
  • Swiss mice, OF1 and CD1

The decision to use an inbred or outbred strain depends on the specific research question. Inbred mice are for when you want to minimize all genetic variables and pinpoint the effect of a single factor. Outbred mice are for when you want to see how a factor affects a genetically varied population.

Rat lineages

• Inbred strain, meaning they are genetically uniform, and provide a consistent baseline for preclinical studies, which is essential for reproducibility.
  • Fischer 344 (F344) rats

• Outbred rats. They have a wide range of genetic variability, which better represents the genetic diversity found in the human population 
  • Sprague Dawley rats 
  • Wistar rats 

The decision to use an inbred or outbred strain depends on the specific research question. Inbred rats are for when you want to minimize all genetic variables and pinpoint the effect of a single factor. Outbred rats are for when you want to see how a factor affects a genetically varied population.

Routes of Administration

Compounds under evaluation can be administered through several routes to reflect clinical usage and pharmacological profiles:

• Oral gavage 
• Intraperitoneal route
• Intravenous route
• Subcutaneous route
• Intramuscular route
• Intranasal route
• Inhalation / aerosolization route

• Intratracheal route

   

This versatility allows us to design tailored studies that align both the infection route and the therapeutic administration route with the intended clinical application.

Pathogens Studied in Vibiosphen Gastrointestinal Infections

Vibiosphen has access to extensive pathogen collections with validated infection models, and can additionally obtain specific strains (not listed below) through established collaborations with hospitals, research institutes, and other organizations, including clinical isolates. Additionally, we have established expertise in performing infection studies with client-specific strains, including the adaptation and validation of models to ensure strain-specific relevance.

Bacterial Gastrointestinal Infections

Our bacterial gastrointestinal infection models cover a broad range of clinically relevant pathogens, including:

• Clostridioides difficile
• Enterococcus faecium (VRE)
• Salmonella enterica
• Escherichia coli (pathogenic strains including EHEC, EPEC, ETEC)
• Helicobacter pylori
• And further strains available (please ask for specific pathogens including BSL3)
   

These models are especially valuable for evaluating new antibiotics and tackling the global issue of antimicrobial resistance.

Fungal Gastrointestinal Infections

• Candida albicans
• Candida glabrata
• Candida tropicalis
• And further strains available (please ask for specific pathogens)
   

These models are particularly valuable for antifungal efficacy studies, gut colonization dynamics, and the role of dysbiosis in fungal overgrowth.

Readouts in Gastrointestinal Infection Models

To ensure robust and translational results, Vibiosphen applies a wide range of validated readouts in its gastrointestinal infection studies:

• Microbiological burden: Quantification of CFU or spore counts in feces and intestinal tissue
• Survival and clinical scoring: Monitoring of diarrhea severity, dehydration, weight loss, and clinial scoring 
• Histopathology and immunohistochemistry: Assessment of epithelial damage, mucosal inflammation, and immune cell infiltration
• Intestinal permeability assays: Measurement of barrier function 
• Cytokine and biomarker profiling: Analysis of immune mediators in serum, feces, and intestinal tissue
• Microbiome profiling: 16S rRNA sequencing and metagenomics for dysbiosis and microbiota recovery
• Recurrence studies: Particularly for C. difficile, to evaluate durability of therapeutic effects and relapse prevention
   

These endpoints can be combined and adapted depending on research objectives, providing deep insight into both efficacy and mechanism of action.

Applications of Vibiosphen’s GI Infection Models

Our gastrointestinal infection models are used in a wide range of preclinical applications:

• Efficacy testing of antibiotics, antifungals, probiotics, and microbiome-based therapies
• Pharmacodynamics (PD) correlation studies
• Host immune response and gut barrier integrity analysis
• Microbiome restoration and dysbiosis-targeted therapies
• Comparative efficacy studies versus standard-of-care treatments
   

Why Choose Vibiosphen?

• Proven expertise in infectious disease research
• Flexible and customized study designs adapted to sponsor requirements (see downloads available as example) 
• Advanced facilities to ensure reliable and reproducible results (BSL2 and BSL3) 
• Strong collaborations with pharmaceutical companies, biotech firms, and academic partners

Vibiosphen combines scientific excellence with industry know-how to deliver actionable preclinical data that drive innovation in infectious disease therapeutics.

Contact Us

If you are developing new treatments or vaccines against pulmonary infections, Vibiosphen can help accelerate your research.

Contact us today to discuss your project and explore how our pulmonary infection models can support your development strategy. 

We will be pleased to facilitate your project by providing a customized study design to your project objectives.