Summary

Probiotics can be used to support the health and productivity of birds. They are useful products in their current form but we believe there is wide scope to develop advanced probiotics that have superior performance characteristics.

 
Currently, probiotics have a variable reputation. This is because; (i) there is often not much peer-reviewed science/clinical data to back up claims made regarding efficacy, (ii) modes of action are often not known, and (iii) user experiences with probiotic products can be quite variable – sometimes they help and at other times they don’t. The current requirement for probiotics to be administered constantly demonstrates the limitations of current products and means that their cost is always a serious consideration. All these issues can be addressed by taking a new approach to probiotic development.

 
The existing first-generation probiotics were developed before there was an understanding of the very variable microbial environment that we now know is present in the gut of chickens. This variable microbial background is likely to be a major reason why poultry growers experience variable outcomes when using first generation probiotics. This project aims to identify and develop strains of bacteria that have superior properties and can reliably deliver positive outcomes in the face of the variable microbiotas found in the chicken gut. The key advance we plan to deliver is to move away from the in vitro based methods that have traditionally been used to identify probiotic strains, to instead use advanced high-throughput in vivo screening methods, directly in birds.

Program

Chicken Meat

Research Organisation

Royal Melbourne Institute of Technology

Objective Summary

The current first generation probiotics need to be continuously fed to birds, indicating that they cannot colonise and flourish in the gut microbiota – they must be constantly applied. Probiotic strains that are well adapted to colonise and persist within the gut microbiota would require single or limited applications and hence would represent a significant advance. They are likely to be cheaper, easier to apply, and more effective. Therefore, our objective is to identify and develop probiotic strains of bacteria that are able to reliably colonise and persist within the variable environment of the gut microbiota of chickens.

 
In previous work with chicken derived Lactobacillus and Escherichia coli isolates we have demonstrated that bacterial with these characteristics, of reliable colonisation and persistence in the face of variable gut microbiota, are somewhat unusual, with only a small proportion of strains having these properties. We have carried out preliminary work to develop discovery methods to efficiently identify these unusual strains. Our objective in this proposed new project is to scale-up those methods to allow high-throughput screening of a large number of isolates and thus build a collection of persistent bacterial isolates that can then be further screened to identify those with the most favourable probiotic characteristics. The most efficient way to identify such strains is by direct in vivo screening, in chickens, for the desirable properties. We will replace the widely used, but largely unproven, in vitro screening methods previously used to identify potential probiotic strains.