Using gnotobiotic ruminants to dissect host–microbe interactions for sustainable agriculture

argues that revisiting gnotobiotic ruminant models is both timely and necessary for establishing causal mechanisms that govern host-microbe interactions in the rumen. Integrating gnotobiotic ruminant models is essential for establishing causal relationships between host biology and rumen microbial composition, thereby providing a foundation for biologically informed strategies that can enhance the sustainability of ruminant production systems.