Differences in fecal bacterial composition between inbred Hatano strains of rats with high/low emotional reactivity

Shuichi Chiba, Tsutomu Shimada, Ryo Ohta, Taichi Hatakeyama, Rie Yanagisawa, Daiya Suzuki, Maiko Kawaguchi

第84回日本動物心理学会

Animal behavior is known to be influenced by gut microbiota, a process known as brain-gut interaction. For example, anxiety-related behaviors increase in germ-free rodents. Hatano rats were selectively bred based on the results of shuttle-box avoidance tests and became inbred strains. We have reported that the high-avoidance animals (HAA) strain of Hatano rats exhibited more anxiety-like behavior and fear responses to footshocks than low-avoidance animals. In this study, we measured the anxiety level in the elevated plus maze (EPM) test of Hatano rats, and then their fecal samples were collected from the colon. The 16S rRNA sequences of the fecal samples were read by Miseq and analyzed by QIIME software to determine the bacterial composition. In the EPM, HAA showed a decreased percentage of entries into open arms, reproducing our previous findings that they are more anxious. Fecal analysis showed statistically significant differences in 5 groups at the phylum level, 8 groups at the class level, 9 groups at the order level, and 10 groups at the family level. Relationships between anxiety and bacterial composition are discussed.