Project description:Dietary methionine restriction represses growth and improves therapeutic responses in several pre-clinical settings. However, how this dietary intervention impacts cancer progression in the context of the immune system is unknown. Here we analyzed the CD45+ immune cells from the small intestine of control (CTRL) diet or methionine-restricted (MR) diet fed tumor-free C57BL/6J donor mice and tumor-bearing Apc <min+/-> recipient mice transplanated with feces from these diet-fed tumor-free C57BL/6J mice by scRNA-seq. Our analysis indicate that fecal microbes from methionine-restricted tumor-free C57BL/6J mice are sufficient to represss T cell activation in the small intestine of Apc <min+/-> mice.
Project description:Impact of antibiotics (T2) or antibiotics in combination with stress (T3) in early life on intestinal functioning in pigs on 8, 55, 176 days in jejunum and ileum (blood only day 8) and control pigs (T1)
Project description:Inappropriate cross talk between mammals and their gut microbiota may trigger intestinal inflammation and drive extra-intestinal immune-mediated diseases. Studies with germ-free or gnotobiotic animals represent the gold standard for research on bacterial-host interaction but they are not readily accessible to the wide scientific community. We aimed at refining a protocol that in a robust manner would deplete murine intestinal microbiota and prove to have significant biologic validity. Previously published protocols for depleting mice of their intestinal microbiota by administering broad-spectrum antibiotics in drinking water were difficult to reproduce. We show that twice daily delivery of antibiotics by gavage depleted mice of their cultivable fecal microbiota and reduced the fecal bacterial DNA load by approximately 400 fold while ensuring the animals’ health. Mice subjected to the protocol for 17 days displayed enlarged ceca, reduced Peyer’s patches and small spleens. Antibiotic treatment significantly reduced the expression of antimicrobial factors and altered the expression of 517 genes in total in the colonic epithelium. Genes involved in cell cycle were significantly altered concomitant with reduced epithelial proliferative activity in situ assessed by Ki-67 expression, suggesting that commensal microbiota drives cellular proliferation in colonic epithelium. We present a robust protocol for depleting mice of their cultivatable intestinal microbiota with antibiotics by gavage and show that the biological effect of this depletion is phenotypic characteristics and epithelial gene expression profile similar to those of germ-free mice. Comparison of genome-wide gene expression of colon intestinal epithelial cells from mice subjected to microbiota depletion protocol against to control mice.