Gastrointestinal microbiota and their manipulation for improved growth and performance in chickens

Authors: SHAHNA, FATHIMA - UNIVERSITY OF GEORGIA; Shanmugasundaram, Revathi; ADAMS, DANIEL - UNIVERSITY OF GEORGIA; SELVARAJ, RAMESH - UNIVERSITY OF GEORGIA

Submitted to: Foods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/2022
Publication Date: 5/12/2022
Citation: Shahna, F., Shanmugasundaram, R., Adams, D., Selvaraj, R. 2022. Gastrointestinal microbiota and their manipulation for improved growth and performance in chickens. Foods. 11(10):1401. https://doi.org/10.3390/foods11101401.
DOI: https://doi.org/10.3390/foods11101401

Interpretive Summary: The gastrointestinal microbial community plays an important role in many physiological and immunological systems. In poultry, the gastrointestinal tract is sterile at hatch, providing the poultry industry with a unique opportunity to have significant control over microbial colonization in young birds. However, due to increased variability in gut microbiota between birds based on breed, housing, environment, diet and immune status, a clear relationship between host and microbiota is not established. Prebiotics, probiotics and synbiotics have been studied at depth over recent years in response to increased limitations on the use of antimicrobials in poultry. These additives can manipulate chicken gut microbiota positively and thereby modulating growth, performance and immune parameters. Designer probiotics customized for specific breeds, age groups, and diseases have the potential to completely replace antibiotics in poultry. With the development of appropriate technology, gut microbiota can be routinely monitored and modulated for host benefit in near future.

Technical Abstract: The gut of warm-blooded animals is colonized by microbes possibly constituting at least 100 times more genetic material of microbial cells than that of the somatic cells of the host. These microbes have a profound effect on several physiological functions ranging from energy metabolism to immune response of the host, particularly those associated with the gut immune system. The gut of a newly hatched chick is typically sterile, but is rapidly colonized by microbes in the environment, undergoing cycles of development. Several factors such as diet, region of the gastrointestinal tract, housing, environment, and genetic factors can influence the microbial composition of an individual bird and can confer a distinctive microbiome signature to the individual birds. The microbial composition can be modified by the supplementation of probiotics, prebiotics, or synbiotics. Supplementing these additives can prevent dysbiosis caused by stress factors such as infection, heat stress, and toxins which cause dysbiosis. The mechanism of action and beneficial effects of probiotics vary depending on strains used. However, it is difficult to establish a relationship between the gut microbiome and host health and productivity due to high variability between flocks due to environmental, nutritional and host factors. This review compiles information on the chicken gut microbiota, dysbiosis and additives such as probiotics, prebiotics and synbiotics, which are capable of modifying gut microbiota and elaborates on the interaction of these additives with chicken gut commensals, immune system and their consequent effects on the health and productivity of chickens. The limitations of probiotic supplementation and the unexplored potential of genetic engineering of poultry probiotics in addressing the public health concerns and zoonosis associated with poultry industry are discussed.