Gut microbiome modulates behaviour and life history in two wild rodents

While the effect of the microbiome on host behavior has been demonstrated in the laboratory, before our study, the ecological consequences of this relationship in natural populations were unknown. We experimentally tested whether the microbiome can directly modulate host behavior and whether the change in behavior affects aspects of life history like home range and survival in wild deer mice (Peromyscus maniculatus) and southern red-backed voles (Myodes gapperi). We compared the microbiome composition, exploration and anxiety-related behaviors, and home range of wild mice and voles before and after chronic antibiotic treatment and measured their survival during the treatment period. This study is the first to test for a direct influence of the gut microbiome on behavior and the consequences of this relationship on life history of wild animals.