Social isolation induces sex-specific differences in behaviour and gut microbiota composition in stress-sensitive rats

Social isolation (SI) is an established rat model of chronic stress. We applied this to the stress-sensitive Wistar Kyoto (WKY) strain to explore brain-to-gut interactions associated with mood. Whether SI stress-induced behavioural changes are sex-specific or if they affect the microbiome in WKY is unknown. We hypothesised individually housed (IH) animals would be more anxious than pair housed (PH), with sex differences. Male and female rats were either IH or PH from 70-112 days old and behaviour was assessed in modified open field (OFTmod), elevated plus maze (EPM) and novel object recognition (NOR) tests. Caecal content DNA was analysed by shotgun metagenome sequencing postmortem.