Microfold (M) cells are rare intestinal epithelial cells that reside in the follicle-associated epithelium of Peyer’s patches1. M cells transport luminal antigens to submucosal antigen-presenting cells2,3. These insights primarily derive from transmission electron microscopy and studies using genetically modified mice2, 3–4. Here we establish an intestinal organoid model to study human M cells and reconstruct the differentiation trajectory of M cells through transcriptome profiling. The results indicate that as well as facilitating luminal antigen transport, human M cells also directly present antigens via the class II major histocompatibility complex (MHC-II). Notably, the related enterocytes only express MHC-II in chronic inflammatory states and do not express typical dendritic cell markers. Human M cells physiologically express a gene profile that resembles that of dendritic cells. Similar to dendritic cells, M cell development is induced by RANKL and CSF2 and requires the transcription factors SPIB and RUNX2. HLA-DQ2.5 M cells process and present gluten antigen as demonstrated in organoid–T cell co-culture assays. These findings suggest that M cells may have a central role in coeliac disease.

BEST4/CA7+ cells of the human intestine were recently identified by single-cell RNA sequencing. While their gene expression profile predicts a role in electrolyte balance, BEST4/CA7+ cell function has not been explored experimentally owing to the absence of BEST4/CA7+ cells in mice and the paucity of human in vitro models. Here, we establish a protocol that allows the emergence of BEST4/CA7+ cells in human intestinal organoids. Differentiation of BEST4/CA7+ cells requires activation of Notch signaling and the transcription factor SPIB. BEST4/CA7+ cell numbers strongly increase in response to the cytokine interferon-γ, supporting a role in immunity. Indeed, we demonstrate that BEST4/CA7+ cells generate robust CFTR-mediated fluid efflux when stimulated with bacterial diarrhea-causing toxins and find the norepinephrine-ADRA2A axis as a potential mechanism in blocking BEST4/CA7+ cell-mediated fluid secretion. Our observations identify a central role of BEST4/CA7+ cells in fluid homeostasis in response to bacterial infections.