Intestinal ischemia, also called mesenteric ischemia, is a severe gastrointestinal and vascular medical emergency caused by a sudden decrease of blood flow through the mesenteric vessels. It generates hypoperfusion of intestinal tissues and can rapidly progress to intestinal wall infarction, systemic inflammation or even death if not treated in time. The mortality of this condition is still considerably high despite all the medical advances of the past few years. This is partially due to the difficulty of diagnosing early stage mesenteric ischemia. Indeed, a speedy and correct diagnosis is decisive for suitable medical care. However, early symptoms are unspecific and conventional clinical markers are neither specific nor sensitive enough. In the last few years, significant clinical and preclinical efforts have been made to find biomarkers which could predict gastrointestinal damage before it becomes irreversible. Here, the gut-derived hormone glucagon-like peptide-1 (GLP-1) is described as a potential early biomarker of this severe condition. Indeed, GLP-1 plasma levels rise rapidly in both mice and humans with intestinal ischemia. This discovery could counter the cruel lack of clinical biomarkers available to diagnose and therefore manage intestinal ischemia efficiently in the early stages. GLP-1 could thus become part of a panel of biomarkers for intestinal ischemia and could help to reduce the associated high mortality rates.