The Gut Microbiota May Affect Personality in Mongolian Gerbils.

The "gut-microbiota-brain axis" reveals that gut microbiota plays a critical role in the orchestrating behavior of the host. However, the correlation between the host personalities and the gut microbiota is still rarely known. To investigate whether the gut microbiota of Mongolian gerbils (Meriones unguiculatus) differs between bold and shy personalities, we compared the gut microbiota of bold and shy gerbils, and then we transplanted the gut microbiota of bold and shy gerbils into middle group gerbils (individuals with less bold and shy personalities). We found a significant overall correlation between host boldness and gut microbiota. Even though there were no significant differences in alpha diversity and beta diversity of gut microbiota between bold and shy gerbils, the Firmicutes/Bacteroidetes phyla and Odoribacter and Blautia genus were higher in bold gerbils, and Escherichia_shigella genus was lower. Furthermore, the fecal microbiota transplantation showed that changes in gut microbiota could not evidently cause the increase or decrease in the gerbil's boldness score, but it increased the part of boldness behaviors by gavaging the "bold fecal microbiota". Overall, these data demonstrated that gut microbiota were significantly correlated with the personalities of the hosts, and alteration of microbiota could alter host boldness to a certain extent.