The use of Galleria mellonella to study microbial interactions, immune responses, and substrate interactions.

Interbacterial interactions are diverse and complex and often dependent on the given niche these bacteria inhabit; therefore, it is often necessary to validate in vitro findings in vivo. Multiple mammalian in vivo models have been established for this purpose, from mice to larger vertebrates like pigs. However, the use of mammalian models comes with high costs and strict ethical considerations, which can limit cohort sizes and experimental outputs. As a result, there has been a significant rise in the use of the Galleria mellonella (greater wax moth larva) research model, not only as a model for drug toxicity and virulence determination but also as a model for studying more complex bacterial and interkingdom interactions in vivo. The versatility of this model and the capacity to carry out high-throughput experiments make this a particularly attractive platform to study bacterial community dynamics. The use of this invertebrate research model organism to study bacterial interactions alleviates the bottleneck between in vitro and in vivo research while also contributing to the replacement and reduction of higher animals needed for in vivo studies. In the present review, we discuss the use of G. mellonella to investigate microbial interactions in vivo, including studies that investigate interbacterial relationships, interkingdom interactions, the host immune response, and the role of bacteria-substrate interactions.