Lisa R. Bielke

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The intestinal mucosa represents the most active defense barrier against the continuous challenge of food antigens and pathogenic microorganisms present in the intestinal lumen. Protection against harmful agents is conferred by factors such as gastric acid, peristalsis, mucus, intestinal proteolysis, and the intestinal biota. The establishment of beneficial(More)
Previous studies conducted in our laboratory have demonstrated that intestinal barrier function can be adversely affected by diet ingredients or feed restriction, resulting in increased intestinal inflammation-associated permeability. Two experiments were conducted in broilers to evaluate the effect of three concentrations of Aflatoxin B1 (AFB1; 2, 1.5, or(More)
The intentional early colonization of the intestinal tract with beneficial microflora, known as competitive exclusion, has been shown to successfully protect poultry from selected enteric pathogens. Although effective cultures have been produced and are available, an inexpensive, air-tolerant, and completely defined culture is needed. Presently, we(More)
Conventionally, bacteriophages are considered viruses capable of amplification only in a narrow range of closely related bacteria. Presently, we selected bacteriophages with the ability to infect more than 1 bacterial genus. Initially, wild-type bacteriophages were selected for ability to form plaques in Salmonella enteritidis agar overlays. For(More)
Gut inflammation is a cardinal event occurring in various gastrointestinal diseases regardless of etiology. A potential mechanism of action for antibiotic growth promoters and probiotics is alleviation or attenuation of such inflammation. In vivo inflammation models and markers to quantify changes in inflammation, such as paracellular leakage and tight(More)
We have previously shown that intestinal barrier function can be adversely affected by poorly digested diets or feed restriction, resulting in increased intestinal inflammation-associated permeability. Three experiments were conducted in broilers to evaluate the effect of dexamethasone (DEX) treatment on systemic fluorescein isothiocyanate-dextran (FITC-D;(More)
Two independent trials were conducted to evaluate the utilization of rye as energy source on bacterial translocation (BT), intestinal viscosity, gut integrity, gut microbiota composition, and bone mineralization, when compared with a traditional cereal (corn) in broiler chickens. In each experiment, day-of-hatch, broiler chickens were randomly assigned to(More)
Spores are popular as direct-fed microbials, though little is known about their mode of action. Hence, the first objective of the present study was to evaluate the in vitro germination and growth rate of Bacillus subtilis spores. Approximately 90% of B. subtilis spores germinate within 60 min in the presence of feed in vitro. The second objective was to(More)
Oral administration of dextran sodium sulfate (DSS) is commonly used as an inducer of enteric inflammation in rodents. However, there is a dearth of knowledge regarding appropriate dosage, timing, or ageresponses in broilers for this potential inducer of inflammation without necrosis. Two experiments were conducted in day-of-hatch chicks to analyze clinical(More)
Enteric inflammation models can help researchers' study methods to improve health and performance and evaluate various growth promoters and dietary formulations targeted to improve performance in poultry. Oral administration of fluorescein isothiocyanate-dextran (FITC-d; 3-5 kDa) and its pericellular mucosal epithelial leakage are an established marker to(More)