摘要Background As an essential source of nutrients for young mammals,milk possesses a variety of biological functions.Recently identified milk-derived small extracellular vesicles(sEV)have shown potential regulatory effects on intestinal health.Current studies have highlighted the functional roles of milk-derived sEV and their RNA cargo in promoting intestinal health.However,there is a paucity of research demonstrating how milk-derived sEV influence intestinal bar-rierfunction through the transport of circRNAs.Results In this study,we aimed to investigate the effects of porcine milk sEV(PM-sEV)circRNA on intestinal barrier function.We systematically identified the circRNAs involved in this process and analyzed the miRNAs through which PM-sEV deliver circRNAs to regulate intestinal barrier function.Our findings revealed that PM-sEV promote the expres-sion of the intestinal tight junction proteins ZO-1 and Occludin,both in vivo(mice)and in vitro(IPEC-J2).When PM-sEV RNA was reduced using ultrasound treatment,their ability to enhance intestinal barrier function was significantly reduced.Bioinformatics analysis showed that circ-0000197,present in PM-sEV,can target miR-429,while miR-429 has the ability to target the 3′-UTR of ZO-1 and Occludin.Furthermore,experiments involving the overexpression or inhibition of the relevant non-coding RNAs(ncRNAs)demonstrated that circ-0000197 significantly enhances intes-tinal barrier function,whereas miR-429 exerts an inhibitory effect on this function.Overall,our findings identify circ-0000197 in PM-sEV as a crucial circRNA that regulates intestinal barrier function by inhibiting miR-429.Circ-0000197 carried by PM-sEV acts as a competing endogenous RNA(ceRNA)that regulates the expression of ZO-1 and Occludin by sponging miR-429,thereby promoting intestinal barrier function at both the cellular and in vivo levels.Conclusions These findings emphasize the vital role of circRNAs transported through milk-derived sEVin regulat-ing intestinal health,offering new avenues for developing innovative functional milk components.This mechanism also underscores the importance of PM-sEV carrying circ-0000197 in preserving intestinal barrier integrity.Collectively,this study enhances our understanding of the complex regulatory networks involving PM-sEV carrying circRNAs and their impact on intestinal health.