administration alters zebrafish anxiety-like behavior gut microbial taurine metabolism.

Interventions to the gut microbiome manipulate the gut-brain axis and could be useful in the treatment of anxiety and depression. In this study, we demonstrated that administration of the bacterium reduces anxiety-like behavior in adult zebrafish. administration increased the diversity of the zebrafish gut microbiome. Linear discriminant analysis Effect Size (LEfSe) analysis revealed that the populations of Actinomycetales including Nocardiaceae, , Gordoniaceae, , Nakamurellaceae, and Aeromonadaceae were reduced, whereas those of Rhizobiales including Xanthobacteraceae, Bradyrhizobiaceae, Rhodospirillaceae, and Pirellulaceae were increased in the gut microbiome. Functional analysis using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) predicted that administration altered taurine metabolism in the zebrafish gut, and we demonstrated that administration increased the taurine concentration in the brain. Since taurine functions as an antidepressant neurotransmitter in vertebrates, our results suggest that could improve anxiety-like behavior in zebrafish the gut-brain axis.