Immunometabolic Signal Transduction Profiling of the Cecum in Chickens Following Challenge With Functional Gut Health Modifiers

Abstract

Although improved control measures have been implemented, Salmonella enterica Enteritidis (S. Enteritidis) continues to present an issue every year in US poultry industry. One of the main reasons for this may be the ability of Salmonella to survive the initial host immune response and persist. While it is common knowledge that birds infected with S. Enteritidis do not manifest any clinical disease symptoms, the mechanisms of persistence occurring in the host during infection have not been widely characterized. The host-pathogen interactions are incredibly complex which makes it difficult to elucidate immune responses and virulence mechanisms. Recent findings in our group have speculated a phenotypic alteration occurring in chicken ceca: early (4 to 48 h) and late (4 to 14 d) infections with S. Enteritidis with three distinct immunometabolic phases post-infection: disease resistance, disease tolerance, and homeostasis. This phenomenon may attribute to the disease resistance in the host. Without resolving chronic colonization by Salmonella, this results in contaminated poultry products to the public. Consequently, the objective was to elucidate the mechanisms of how S. Enteritidis affects immunometabolic tissue phenotype change in early broiler growth. This objective was approached by testing two different gut physiological modulators in post-hatch broiler chicks: an antibiotic growth promoter (AGP) and a phytobiotic feed additive and their role in the affecting the host phenotype. Using this methodology, an immunometabolic cecal phenotype change was detected in S. Enteritidis challenged birds fed with an AGP based on the shifting microbiota composition and pro-inflammatory response. Furthermore, the addition of a phytobiotic also demonstrated immunometabolic cecal alteration based on the phosphorylation data of the identified metabolic and immune pathways involved in host immunity. For the first time, it is shown that a phytobiotic product initially modulates metabolism while also potentially supporting growth and feed efficiency downstream.