Objective To investigate the relationship between exposure to foodborne antibiotics and gut microbiota,as well as its impact on irritable bowel syndrome(IBS).Methods A total of 100 IBS patients(IBS group)and 100 healthy controls(control group)were enrolled in this case-control study.Antibiotic ex-posure was assessed by serum detection,and gut microbiota composition was analyzed by 16S rRNA gene se-quencing technology.Binary Logistic regression model and chi-square test were used for statistical analysis to explore the relationship between antibiotic exposure and IBS,and to analyze the differences in gut microbiota.Results The antibiotic exposure rate of IBS group was significantly higher than that of control group(59％vs.36％,P=0.016),and the exposure to β-lactam antibiotics was significantly different between the two groups(P=0.047).In addition,the composition of gut microbiota in the IBS group was significantly different from that in the control group,and the abundance of Firmicutes was increased(P＜0.001),while the abun-dance of Lactobacillus,Bifidobacterium and Faecalibacterium was decreased(P＜0.001).Conclusion Food-borne antibiotic exposure may be one of the risk factors for IBS,and antibiotic exposure may affect the occur-rence and development of IBS by changing the composition of gut microbiota.Foodborne antibiotic exposure may be a risk factor for inducing IBS and could affect the disease process by altering the structure of the gut microbiota.Therefore,enhancing the regulation of foodborne antibiotic use and raising public awareness about the importance of minimizing foodborne antibiotic exposure can effectively prevent and reduce the incidence of IBS.