Potential replacements for antibiotic growth promoters in poultry: Interactions at the gut level and their impact on host immunity

Authors: Swaggerty, Christina - Christi; BORTOLUZZI, CRISTIANO - Texas A&M University; LEE, ANNAH - Texas A&M University; EYNG, CINTHIA - Western Paraná State University; DAL PONT, GABRIELA - Texas A&M University; Kogut, Michael - Mike

Submitted to: Advances in Experimental Medicine and Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2020
Publication Date: 11/23/2021
Citation: Swaggerty, C.L., Bortoluzzi, C., Lee, A., Eyng, C., Dal Pont, G., Kogut, M.H. 2021. Potential replacements for antibiotic growth promoters in poultry: Interactions at the gut level and their impact on host immunity. Advances in Experimental Medicine and Biology. 1354:145-159. https://doi.org/10.1007/978-3-030-85686-1_8.
DOI: https://doi.org/10.1007/978-3-030-85686-1_8

Interpretive Summary: There are about 1 billion bacteria and other microbes living in the gut of a chicken. These bacteria and microbes can impact the chicken’s health with the molecules they release into the gut. This "metabolite signaling" impacts the gut as well as other organ systems that control host physiology, metabolism, and immunity. When the gut microbes are stable and the gut is healthy, there are no problems with the chicken; however, when an imbalance occurs, the chicken may experience overall health issues. Research has shown the gut environment is easily changed by diet, antibiotics, infections, and other factors; therefore, one way to promote a healthy gut and stable microbial population is to add beneficial bacteria or other feed additives to the chicken’s food. A healthy and stable gut is responsible for absorbing nutrients and recognizing beneficial bacteria while still responding to and eliminating harmful bacteria or toxic compounds. This review highlights the importance of adding different feed additives to the diets of poultry in order to enhance health and productivity. These new approaches will keep chickens healthier and, therefore, create a safer product that will reach the consumer.

Technical Abstract: The chicken gastrointestinal tract (GIT) is home to a complex, biodiverse microbial community of ~1 million bacterial genes plus archaea and fungi that links the host diet to its health. This microbial population contributes to host physiology through metabolite signaling while also providing local and systemic nutrients to multiple organ systems. In a homeostatic state, the host-microbial interaction is symbiotic; however, physiological issues are associated with dysregulated microbiota. Manipulating the microbiota is a therapeutic option, and the concept of adding beneficial bacteria to the intestine has led to probiotic and prebiotic development. The gut microbiome is readily changeable by diet, antibiotics, pathogenic infections, and host- and environmental-dependent events. The intestine performs the key roles of nutrient absorption and tolerance of beneficial microbiota, yet responding to undesirable microbes or microbial products and preventing translocation to sterile body compartments. During homeostasis, the immune system is actively preventing or modulating the response to known or innocuous antigens. Manipulating the microbiota through nutrition, modulating host immunity, preventing pathogen colonization, or improving intestinal barrier function has led to novel methods to prevent disease, and resulted in improved body weight, feed conversion, and carcass yield in poultry. This review highlights the importance of adding different feed additives to the diets of poultry in order to manipulate and enhance the health and productivity of flocks.