The mammalian gut microbiota was previously shown to promote angiogenesis in the small intestine by an unknown mechanism. By comparing germ-free and colonized mice, Reinhardt et al. show that intestinal bacteria promote glycosylation of the pro-angiogenic tissue factor (TF), thus targeting this receptor to the enterocyte cell surface. Treatment of colonized mice with a TF-specific antibody, or deletion of the phosphorylatable cytoplasmic domain of TF, reduced intestinal vessel density. The authors also found that germ-free mice had lower expression of the downstream receptor PAR1. Moreover, phosphorylation of TF was impaired and vessel density was reduced accordingly in PAR1-deficient mice. These data provide evidence for a new developmental pathway of bacterium-stimulated vascular remodelling in the gut that could potentially be exploited to improve intestinal homeostasis.