The intestinal glucose absorption is not easily evaluated in vivo. However, it is one component driving the blood glucose evolution through time during an Oral glucose tolerance test (OGTT). This procedure is routinely used to assess human or animal glucose tolerance and to detect defects in glucose homeostasis in particular those related to insulin sensitivity but it could also bring significant knowledge on intestine glucose absorption. It is not known if glucose absorption by the intestine is optimal and total during oral glucose tolerance test. Moreover, the variability in glucose absorption according to patient and animal condition is not taken into consideration. Based on OGTT glucose time courses, we developed an extension of classical Glucose/Insulin model that takes into account intestinal absorption and established absorption parameters and insulin sensitivity. Using glucose-only dataset, we found the smallest set of differential equations and parameters that can account for the data. After calibration on control mice, we applied our model on (KO) mice invalidated for an intestinal glucose transporter (GLUT2). We show that, expectedly, glucose absorption was much lower in the KO compared to the control mice whereas parameters such as insulin sensitivity remained unchanged. We also fitted our model to OGTT on patient and animal that underwent a bariatric surgery (surgical removal of parts of the intestine) to assess the impact of the surgery on glucose absorption during OGTT. Our model suggests a lower absorption than initially anticipated and can be provided as a new clinical analysis tool for OGTT data.