show Abstracthide AbstractOur goal is twofold. First, we established morphine-induced conditioned place preference (CPP) rat models, and adopted 16s rRNA sequencing of fecal bacterial communities before and after drug exposure, with an attempt to describe the impact of morphine on the alterations in gut microbiota. Second, given that the CPP scores reflects the sensitivity to rewarding values of the drug, we compared the gut microbiota of rats with different CPP scores and explored correlation between microbial alterations and the sensitivity to morphine reward.