Recovery of gut microbiota in mice exposed to tetracycline hydrochloride and their correlation with host metabolism.

Antibiotics can disturb the gut microbial community and host metabolism. However, their recovery after antibiotics exposure needs to be characterized, and the correlation between gut microbiota and host metabolism remains unclear. In this study, mice were exposed to 0.5, 1.5 and 10 g/L tetracycline hydrochloride (TET) for 2 weeks, then recovered without TET for another 2 weeks. The results showed that 2-week TET exposure changed microbial community and functions in the mouse gut, and increased abundance of antibiotic resistance genes (ARGs), especially in the 10 g/L TET group. After a 2-week recovery, these changes could only be recovered to the control level in the 0.5 g/L TET exposure group, except for ARGs. Besides gut microbiota, TET exposure also changed metabolic profiles in mouse urine. The 2-week recovery significantly reduced changes in metabolic profiles. Some altered metabolites were found to have a very high correlation with gut microbial community and functions, indicating that TET exposure might induce certain changes in urinary metabolic profiles by altering the gut microbiota. The results from this study suggest that the influences of low-level TET exposure are reversible, except for ARGs, which should be paid more attention. During the application of TET, their dosage should be effectively considered and controlled.