Exposure to the gut microbiota drives distinct methylome and transcriptome changes in intestinal epithelial cells during postnatal development

Validation of a subset of differentially expressed and methylated genes. Small intestinal epithelial tissue was harvested by scraping from an independent cohort of GF and CONV-R mice from another gnotobiotic animal facility and both DNA and RNA were isolated for qPCR expression analysis and targeted methylation analysis using amplicon sequencing. Asterisks denote observations in the validation data that showed the same trend/direction as in the initial data, but were only very close to reaching the significance threshold after correction for multiple testing and therefore were considered as validation. (XLSX 48 kb

Neurotensin Is Coexpressed, Coreleased, and Acts Together With GLP-1 and PYY in Enteroendocrine Control of Metabolism

The 2 gut hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are well known to be coexpressed, costored, and released together to coact in the control of key metabolic target organs. However, recently, it became clear that several other gut hormones can be coexpressed in the intestinal-specific lineage of enteroendocrine cells. Here, we focus on the anatomical and functional consequences of the coexpression of neurotensin with GLP-1 and PYY in the distal small intestine. Fluorescence-activated cell sorting analysis, laser capture, and triple staining demonstrated that GLP-1 cells in the crypts become increasingly multihormonal, ie, coexpressing PYY and neurotensin as they move up the villus. Proglucagon promoter and pertussis toxin receptor-driven cell ablation and reappearance studies indicated that although all the cells die, the GLP-1 cells reappear more quickly than PYY- and neurotensin-positive cells. High-resolution confocal fluorescence microscopy demonstrated that neurotensin is stored in secretory granules distinct from GLP-1 and PYY storing granules. Nevertheless, the 3 peptides were cosecreted from both perfused small intestines and colonic crypt cultures in response to a series of metabolite, neuropeptide, and hormonal stimuli. Importantly, neurotensin acts synergistically, ie, more than additively together with GLP-1 and PYY to decrease palatable food intake and inhibit gastric emptying, but affects glucose homeostasis in a more complex manner. Thus, neurotensin is a major gut hormone deeply integrated with GLP-1 and PYY, which should be taken into account when exploiting the enteroendocrine regulation of metabolism pharmacologically