Brendan Wren's research interests predominantly involve determining the genetic basis by which bacterial pathogens cause disease. His research group exploits a range of post genome research strategies to gain a comprehensive understanding of how these pathogens function, how they evolve and how they interact with their respective hosts.

A core interest includes studying glycosylation and glycostructures and how this relates to the survival and virulence of bacterial pathogens. An application of this basic research is the development of Protein Glycan Coupling Technology and other glycobiotechnological innovations for the production of recombinant glycoproteins. This has been applied for the development of inexpensive glycoconjugate vaccines for human and veterinary use.