摘要Mammals have existed on Earth for millions of years.During this long period,mammals and their gut commensal microbes have coevolved and coadapted,forming a complex and inseparable interrelationship called "superorganisms." On the one hand,the food and gut environment play an important role in shaping the composition and function of gut microbiota.On the other hand,gut microbiota actively participates in host nutrition metabolism and profoundly affect host immunity.However,this natural coevolving process has been significantly changed in recent decades by antibiotic administration.Although antibiotic therapy is considered as a milestone in fighting infectious diseases,its negative effects on gut microbiota and host health have been recognized.Here,we will discuss the unfavorable effects and underlying mechanism of antibiotics on gut microbiota and host immunity,as well as possible solutions to reverse adverse effects brought about by antibiotic treatment.