Physiological stress mediated by corticosterone administration alters intestinal bacterial communities and increases the relative abundance of clostridium perfringens in the small intestine of chickens
Citation
Zaytsoff, S.J.M., Uwiera, R.R.E., Douglas Inglis, G. (2020). Physiological stress mediated by corticosterone administration alters intestinal bacterial communities and increases the relative abundance of clostridium perfringens in the small intestine of chickens. Microorganisms, [online] 8(10), 1-16. http://dx.doi.org/10.3390/microorganisms8101518
Plain language summary
Controlled physiological stress mediated by the administration of the glucocorticoid stress hormone, corticosterone (CORT) altered bacterial communities in the small intestine, including an increase in the density of the important chicken bacterial pathogen, Clostridium perfringens. Predictive functional analysis identified possible modulations to bacterial function following CORT administration. Given that stress can modulate a variety of host functions, including metabolism, future studies should implement a multi-omics approach to better understand the interactions between the host and the microbiota during their development in chickens, and importantly, examine how this relationship evolves over time under conditions of physiological stress. As birds were not exposed to any antimicrobials in the current study (i.e., as a confounding effect), study findings implicated physiological stress as an important mediator of the microbiota, including C. perfringens, and supported stress as a predisposing factor to NE. Future research should include challenging birds with both stress and a known virulent strain of C. perfringens to ascertain the mechanisms by which stress predisposes birds to NE. Lastly, deciphering interactions between hosts ± stress and the microbiota will be beneficial to developing novel, non-antibiotic, and tailored strategies in poultry production.
Abstract
A model of physiological stress mediated by the administration of corticosterone (CORT) was used to investigate the impact of stress on the intestinal microbiota of chickens. Birds were administered CORT in their drinking water at 0, 10 (low dose CORT; LDC), and 30 (high dose CORT; HDC) mg/L. Digesta from the small intestine and ceca were examined after 1, 5, and 12 days post-initiation of CORT administration by 16S rRNA gene sequencing. A decrease in phylogenetic diversity and altered composition of bacteria were observed for HDC in the small intestine. Analysis by ANOVA-Like Differential Expression 2 (ALDEx2) showed that densities of Clostridium sensu stricto 1 bacteria were increased in the small intestine for LDC and HDC. Quantitative PCR confirmed that CORT administration increased densities of Clostridium perfringens in the small intestine, but only HDC was associated with increased densities of the bacterium in ceca. Predictive functional analysis by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUSt2) showed pathways of carbohydrate metabolism to be enriched with CORT, and amino acid synthesis to be enriched in control birds in the small intestine. In conclusion, physiological stress mediated by CORT modulated bacterial communities in the small intestine and increased densities of C. perfringens. This implicates stress as an important mediator of this important enteric pathogen in poultry.