Dog ownership during adolescence alters the microbiota and improves mental health

Abstract Adolescents who own dogs have higher well-being than those who do not; however, it is unclear how dog ownership affects adolescents’ well-being. As dog ownership influences the composition of the microbiota in the home environment, we examined the microbiome of dog-owning adolescents and analyzed associations with mental health and behavior. Our findings reveal that dog ownership led to changes in participants’ social behavior and some commensals were associated with adolescents' psychological scores. Mice treated with the microbiota of dog-owning adolescents showed higher social interactions. An association analysis was conducted between the adolescents' psychological scores and the mouse behavior with the abundance of each amplicon sequence variant of the microbiome (ASV), and we found that ASVs belonging to Streptococcus were similarly associated with the social approach in both adolescents and ex-germ-free mice. These results suggest that the microbiota may be partly involved in improving the well-being of adolescents living with dogs.