Caenorhabditis elegans as an experimental model for resilience-boosting microbiota interventions in non-model ectotherms

Ectotherms make up most animal species and deliver essential services to ecosystems and human food supply chains but are highly vulnerable to environmental perturbations. Being vastly underrepresented in laboratory-based studies, we also critically lack knowledge and approaches to improve their resilience to emerging threats from climate change and anthropogenic activities. With the gut microbiota critically modulating animal health, including stress tolerance, gut microbial interventions may offer opportunities to improve non-model ectotherm resilience to such pressures. Developing such interventions requires knowledge of host-gut microbiota-environment interactions that is critically lacking for most species and needs establishing. The roundworm Caenorhabditis elegans is emerging as a powerful ectotherm model to study host-gut microbiota interactions. Extensively utilised across research fields, C. elegans offers a breadth of resources and methodologies, including bioengineering technologies, defined microbiotas, host and microbial isolate collections. In this review, we recapitulate C. elegans uses in gut microbiota studies, highlighting strengths and limitations, how it may accelerate mechanistic study of non-model ectotherm microbiotas. We notably propose a C. elegans-based strategy to identify, isolate and study isolates from non-model ectotherm species to design microbial interventions that may promote climate resilience in non-model species.