Background Oral inhibitors of JAK1 have become promising therapeutic agents for the treatment of inflammatory bowel diseases (IBD); however, concerns have been raised regarding their specificity and safety profiles. Currently, a local therapy based on specific JAK1 siRNA combined with lipid nanoparticle (LNP) technology is under investigation as a safer alternative to JAK inhibitors.The purpose of this study is to explore the inhibition of the JAK1 pathway in the intestinal epithelium mediated by siRNA/LNP technology, using human primary 2D culture. Methods Human primary 2D cultures were generated from colonic 3D organoids of non-IBD donors. The efficiency of JAK1 pathway inhibition was tested in IFN-y stimulated cultures using either filgotinib (a JAK1 inhibitor, used as a control) or the novel human JAK1 siRNA. JAK1 siRNA transfection was performed using Lipofectamine or LNPs. qPCR was performed on a panel of JAK1 target genes to evaluate the efficiency of JAK1 pathway inhibition. Results Incubation of the 2D culture with IFN-y induced the activation of the JAK1 pathway, as suggested by the significant up-regulation of JAK1-dependent genes (i.e., CXCL10, SOCS1, SOCS3 and PLA2G2A). The addition of filgotinib to the culture efficiently inhibited the JAK1 pathway by suppressing the expression of JAK1-target genes. JAK1 siRNA transfection using Lipofectamine reduced JAK1 mRNA expression by 50%, which was mirrored by the concomitant down-regulation (between 60 and 80%) of JAK1-dependent genes. Importantly, the silencing efficiency of the JAK1-dependent pathway by LNPs was comparable to that observed using Lipofectamine. Conclusion Organoid-derived 2D culture is a useful model for investigating the activation of the JAK1 pathway and its pharmacological inhibition in human intestinal epithelium. In particular, siRNA/LNP nanoplexes may be a promising technology for locally delivering highly specific siRNAs to the intestinal mucosa, which could pave the way for the development of more effective treatments for IBD patients.