Exploring the complexities of poultry respiratory microbiota: colonization, composition, and impact on health

Abstract

An accurate understanding of the ecology and complexity of the poultry respiratory microbiota is of utmost importance for elucidating the roles of commensal or pathogenic microorganisms in the respiratory tract, as well as their associations with health or disease outcomes in poultry. This comprehensive review delves into the intricate aspects of the poultry respiratory microbiota, focusing on its colonization patterns, composition, and impact on poultry health. Firstly, an updated overview of the current knowledge concerning the composition of the microbiota in the respiratory tract of poultry is provided, as well as the factors that influence the dynamics of community structure and diversity. Additionally, the significant role that the poultry respiratory microbiota plays in economically relevant respiratory pathobiologies that affect poultry is explored. In addition, the challenges encountered when studying the poultry respiratory microbiota are addressed, including the dynamic nature of microbial communities, site-specific variations, the need for standardized protocols, the appropriate sequencing technologies, and the limitations associated with sampling methodology. Furthermore, emerging evidence that suggests bidirectional communication between the gut and respiratory microbiota in poultry is described, where disturbances in one microbiota can impact the other. Understanding this intricate cross talk holds the potential to provide valuable insights for enhancing poultry health and disease control. It becomes evident that gaining a comprehensive understanding of the multifaceted roles of the poultry respiratory microbiota, as presented in this review, is crucial for optimizing poultry health management and improving overall outcomes in poultry production.

Activation of Antiviral Host Responses against Avian Influenza Virus and Remodeling of Gut Microbiota by rLAB Vector Expressing rIL-17A in Chickens

“…This study is in line with the previous findings, where IAV infection causes a marked alteration of gut microbiota mainly by decreasing the level of probiotic bacteria and increasing the level of pathogenic bacteria . However, several shreds of evidence suggest that the intestinal microbiota composition in chickens impacts both local and systemic immune responses, influencing antiviral host defenses. , In addition to the indirect effect of microbiota in mediating local and systemic immune responses via interferons (IFNs), interleukins (ILs), and virus-specific antibodies, available reports also suggest the role of gut microbial metabolites, such as short-chain fatty acids, in the regulation of the antiviral immune responses in chickens …”

“…Similar to mammalian hosts, in avians, the gastrointestinal system cross-communicates with the upper respiratory tract (URT) via the intricate gut–lung axis, facilitating the exchange of neurochemicals, hormones, immune cells, and microbial metabolites. , For the present study, we chose to use the oro-nasal route as a key mucosal inductive site, which is normally populated with local immune cells organized into mucosa-associated lymphoid tissues or unorganized lymphoid sites. For avians, a growing body of the literature also suggests a substantial taxonomic unit sharing among the upper URTs and intestinal microbial population .…”

“…66 However, several shreds of evidence suggest that the intestinal microbiota composition in chickens impacts both local and systemic immune responses, influencing antiviral host defenses. 20,67 In addition to the indirect effect of microbiota in mediating local and systemic immune responses via interferons (IFNs), interleukins (ILs), and virus-specific antibodies, available reports also suggest the role of gut microbial metabolites, such as short-chain fatty acids, in the regulation of the antiviral immune responses in chickens. 20 To this end, our final aim was to evaluate the effects of the elevated host immune responses and altered microbial compositions in the gut in conferring antiviral host defense against influenza-type A/H9N2 infection.…”