Differentiation of strains of Bifidobacterium animalis subsp. lactis by ability to modulate an immune response

Open Access
Amos, Jeffrey S
Area of Honors:
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Robert F Roberts, Thesis Supervisor
  • Donald Ashley Bryant, Honors Advisor
  • Joshua D Lambert, Faculty Reader
  • Scott Brian Selleck, Faculty Reader
  • probiotics
  • IBD
  • IBS
  • Bifidobacterium animalis
Irritable Bowel Disease (IBD) and Irritable Bowel Syndrome (IBS) are two gastrointestinal disorders that are increasing in prevalence in the United States. Symptoms such of these disorders such as vomiting, bloating, and diarrhea inhibit patients from leading normal, social lives. Currently, there are a number of drugs on the market to treat these diseases but they are not effective for all patients. The use of probiotics is one possible alternative to drug therapy. Probiotics, commonly delivered through fermented dairy products and supplemental tablets, are becoming more widespread in usage as a treatment of symptoms caused by IBD and IBS. One bacterial species, Bifidobacterium animalis, is often used as a probiotic in commercial products. However, not all strains of B. animalis are thought to have the same immunomodulatory effect on the human gut. The World Health Organization has determined that the health benefits of probiotics are strain-specific and that not all members of a species have the same beneficial health effects. Using a model created during this experiment, an inflammatory response will be simulated using RAW 264.7 murine macrophages and treated with eight strains of Bifidobacterium animalis ssp. lactis and ssp. animalis. Production of Interleukin-10, an anti-inflammatory cytokine, and Tumor Necrosis Factor α, a pro-inflammatory cytokine, will be quantified using ELISA to determine if different strains of B. animalis ssp. lactis have differing immunomodulatory effects on RAW 264.7 macrophages.